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Sample records for temperature 0065-0273 k

  1. OXIDATION OF INCONEL 718 IN AIR AT TEMPERATURES FROM 973K TO 1620K.

    Energy Technology Data Exchange (ETDEWEB)

    GREENE,G.A.; FINFROCK,C.C.

    2000-10-01

    As part of the APT project, it was necessary to quantify the release of tungsten from the APT spallation target during postulated accident conditions in order to develop accident source terms for accident consequence characterization. Experiments with tungsten rods at high temperatures in a flowing steam environment characteristic of postulated accidents revealed that considerable vaporization of the tungsten occurred as a result of reactions with the steam and that the aerosols which formed were readily transported away from the tungsten surfaces, thus exposing fresh tungsten to react with more steam. The resulting tungsten release fractions and source terms were undesirable and it was decided to clad the tungsten target with Inconel 718 in order to protect it from contact with steam during an accident and mitigate the accident source term and the consequences. As part of the material selection criteria, experiments were conducted with Inconel 718 at high temperatures to evaluate the rate of oxidation of the proposed clad material over as wide a temperature range as possible, as well as to determine the high-temperature failure limit of the material. Samples of Inconel 718 were inserted into a preheated furnace at temperatures ranging from 973 K to 1620 K and oxidized in air for varying periods of time. After oxidizing in air at a constant temperature for the prescribed time and then being allowed to cool, the samples would be reweighed to determine their weight gain due to the uptake of oxygen. From these weight gain measurements, it was possible to identify three regimes of oxidation for Inconel 718: a low-temperature regime in which the samples became passivated after the initial oxidation, an intermediate-temperature regime in which the rate of oxidation was limited by diffusion and exhibited a constant parabolic rate dependence, and a high-temperature regime in which material deformation and damage accompanied an accelerated oxidation rate above the parabolic

  2. Electrical conductivity of molten SnCl{sub 2} at temperature as high as 1314 K

    Energy Technology Data Exchange (ETDEWEB)

    Salyulev, Alexander B.; Potapov, Alexei M. [Ural Branch of RAS, Ekaterinburg (Russian Federation). Inst. of High-Temperature Electrochemistry

    2015-07-01

    The electrical conductivity of molten SnCl{sub 2} was measured in a wide temperature range (ΔT=763 K), from 551 K to temperature as high as 1314 K, that is, 391 above the boiling point of the salt. The specific electrical conductance was found to reach its maximum at 1143 K, after that it decreases with the temperature rising.

  3. Dioctahedral smectite reactions at elevated temperatures: Effects of K-availability, Na/K ratio and ionic strength

    Science.gov (United States)

    Whitney, G.

    1992-01-01

    Hydrothermal experiments were conducted to measure the effects of K availability, Na/K ratio and ionic strength in chloride solutions on the rate and extent of the reaction of smectite to interstratified illite/smectite. The effect of K-content on reaction progress is dramatic at low (0.33 eq.) K concentrations, but diminishes above a concentration of 0.66 equivalents. The effect of K-content is also more important at lower temperatures than at higher temperatures. Addition of K above that required to satisfy the cation exchange capacity of the smectite reduced the amount of chlorite byproduct and produced authigenic K-feldspar at the highest K-concentration. Similar experiments were run using Na/K equivalent ratios of 0 to 25 and total solution molalities of 0 to 3.75 molal. Because these experiments were small fixed-volume experiments, it was necessary to vary two of the three key variables (K-content, Na/K ratio, ionic strength simultaneously. The data suggest, however, that K-content has a much stronger effect than either Na/K ratio or ionic strength on illitization reaction progress. ?? 1992.

  4. Electrical conductivity of molten ZnCl{sub 2} at temperature as high as 1421 K

    Energy Technology Data Exchange (ETDEWEB)

    Salyulev, Alexander B.; Potapov, Alexei M. [RAS Ural Branch, Ekaterinburg. (Russian Federation) Institute of High-Temperature Electrochemistry

    2015-07-01

    The electrical conductivity of molten ZnCl{sub 2} was measured in a wide temperature range (ΔT=863 K) to a temperature as high as 1421 K that is 417 degrees above the boiling point of the salt. At the temperature maximum of the own vapor pressure of the salt reached several megapascals.

  5. Temperature dependent structural, vibrational and magnetic properties of K3Gd5(PO4)6.

    Science.gov (United States)

    Bevara, Samatha; Achary, S Nagabhusan; Mishra, Karuna Kara; Ravindran, T R; Sinha, Anil K; Sastry, P U; Tyagi, Avesh Kumar

    2017-02-22

    Herein we report the evolution of the crystal structure of K3Gd5(PO4)6 in the temperature range from 20 K to 1073 K, as observed from variable temperature X-ray diffraction and Raman spectroscopic studies. K3Gd5(PO4)6 has an open tunnel containing a three dimensional structure built by [Gd5(PO4)6]3- ions which in turn are formed of PO4 tetrahedra and GdOn (n = 8 and 9) polyhedra. The empty tunnels in the structure are occupied by K+ ions and maintain charge neutrality in the lattice. Evolution of unit cell parameters with temperature shows a systematic increase with temperature. The average axial thermal expansion coefficients between 20 K and 1073 K are: αa = 10.6 × 10-6 K-1, αb = 5.5 × 10-6 K-1 and αc = 16.4 × 10-6 K-1. The evolution of distortion indices of the various coordination polyhedra with temperature indicates a gradual decrease with increasing temperature, while those of Gd2O9 and K2O8 polyhedra show opposite trends. The overall anisotropy of the lattice thermal expansion is found to be controlled largely by the effect of temperature on GdOn polyhedra and their linkages. Temperature dependent Raman spectroscopic studies indicated that the intensities and wavenumbers of most of the Raman modes decrease continuously with increasing temperature. Anharmonic analyses of Raman modes indicated that the lattice, rigid translation and librational modes have larger contributions towards thermal expansion of K3Gd5(PO4)6 compared to high frequency internal modes. The temperature and field dependent magnetic measurements indicated no long range ordering down to 2 K and the observed effective magnetic moment per Gd3+ ion and the Weiss constant are 7.91 μB and 0.38 K, respectively.

  6. Electrical conductivity of molten CdCl{sub 2} at temperatures as high as 1474 K

    Energy Technology Data Exchange (ETDEWEB)

    Salyulev, Alexander B.; Potapov, Alexei M. [Russian Academy of Sciences, Ekaterinburg (Russian Federation). Inst. of High-Temperature Electrochemistry

    2016-11-01

    The electrical conductivity of molten CdCl{sub 2} was measured across a wide temperature range (ΔT=628 K), from 846 K to as high as 1474 K, i.e. 241 above the normal boiling point of the salt. In previous studies, a maximum temperature of 1201 K was reached, this being 273 lower than in the present work. The activation energy of electrical conductivity was calculated.

  7. Is There a Temperature Limit in Planet Formation at 1000 K?

    Science.gov (United States)

    Demirci, Tunahan; Teiser, Jens; Steinpilz, Tobias; Landers, Joachim; Salamon, Soma; Wende, Heiko; Wurm, Gerhard

    2017-09-01

    Dust drifting inward in protoplanetary disks is subject to increasing temperatures. In laboratory experiments, we tempered basaltic dust between 873 K and 1273 K and find that the dust grains change in size and composition. These modifications influence the outcome of self-consistent low speed aggregation experiments showing a transition temperature of 1000 K. Dust tempered at lower temperatures grows to a maximum aggregate size of 2.02 ± 0.06 mm, which is 1.49 ± 0.08 times the value for dust tempered at higher temperatures. A similar size ratio of 1.75 ± 0.16 results for a different set of collision velocities. This transition temperature is in agreement with orbit temperatures deduced for observed extrasolar planets. Most terrestrial planets are observed at positions equivalent to less than 1000 K. Dust aggregation on the millimeter-scale at elevated temperatures might therefore be a key factor for terrestrial planet formation.

  8. 20-50 K and 40-80 K pulse tube coolers: Two candidates for a low temperature cooling chain

    Science.gov (United States)

    Tanchon, J.; Trollier, T.; Triqueneaux, S.; Ravex, A.

    2010-01-01

    Following its important cryogenics heritage for the European Space industry for both Ariane launcher and Orbital programs, Air Liquide - Advanced Technology Division (AL/DTA) is proposing different pulse tube cryocoolers all over the temperature range to answer the needs of earth observation and scientific missions. This paper presents recent performance improvement of the large heat lift 40-80 K pulse tube cooler (LPTC). Four units have been manufactured and tested. Three units are dedicated to lifetime testing in the framework of French Military Space Program (under CNES contract) and Meteosat Third Generation program (ESA contract). The batch performances are described and the product maturity is discussed in this paper. To lower the temperature range and to complete our cryogenic chain, we developed in partnership with CEA/INAC/SBT, a heat intercepted 20-50 K pulse tube cryocooler. This cooler has been developed in the framework of an ESA contract (ESA/ESTEC No 20497/0/NL/PA-20-50 K pulse tube cooler). A development phase has been performed to test and optimize different cold head architectures to reach the 300 mW@20 K specification. A no-load temperature of 12.5 K has been demonstrated on breadboard model. The outputs of the trade-off, the resulting design and the performances are described. In complement to the dilution cooler similar to the one developed for the PLANCK mission, those two pulse tube coolers are potential candidates for a very low temperature cooling chain. By optimizing the capabilities of the 20 K stage for low temperature operation (no-load in the range of 8 K) the coupling of the three independent stages becomes possible.

  9. Methane hydrate dissociation rates as 0.1 MPa and temperatures above 272K

    Energy Technology Data Exchange (ETDEWEB)

    Durham, W B; Circone, S; Stern, L A; Kirby, S H; Pinkston, J C

    1999-10-25

    We performed rapid depressurization experiments on methane hydrate under isothermal conditions above 272 K to determine the amount and rate of methane evolution. Sample temperatures rapidly drop below 273 K and stabilize near 272.5 K during dissociation. This thermal anomaly and the persistence of methane hydrate are consistent with the reported recovery of partially dissociated methane hydrate from ocean drilling cores.

  10. Reactions of O‑ with D2 at temperatures below 300 K

    Science.gov (United States)

    Plašil, Radek; Tran, Thuy D.; Roučka, Štěpán; Rednyk, Serhiy; Kovalenko, Artem; Jusko, Pavol; Mulin, Dmytro; Zymak, Illia; Dohnal, Petr; Glosík, Juraj

    2017-11-01

    The reaction of O‑ anions with molecular deuterium D2 has been studied experimentally using a cryogenic 22-pole radiofrequency ion trap. Two reaction channels were observed. In the associative detachment D2O and an electron are formed and for atom transfer formation OD‑ + D was observed. The rate coefficients of the reactions have been determined at temperatures below 300 K. The reaction rate coefficient k 1 of the associative detachment increases with decreasing temperature from k 1(300 K) = 0.5 × 10‑9 cm3 s‑1 at 300 K up to k 1(70 K) = 1.2 × 10‑9 cm3 s‑1 at 70 K both with 30 % overall uncertainty.

  11. Reaction rate constants of HO2 + O3 in the temperature range 233-400 K

    Science.gov (United States)

    Wang, Xiuyan; Suto, Masako; Lee, L. C.

    1988-01-01

    The reaction rate constants of HO2 + O3 were measured in the temperature range 233-400 K using a discharge flow system with photofragment emission detection. In the range 233-253 K, the constants are approximately a constant value, and then increase with increasing temperature. This result suggests that the reaction may have two different channels. An expression representing the reaction rate constants is presented.

  12. Phase Transformations and Phase Equilibria in the Fe-N System at Temperatures below 573 K

    DEFF Research Database (Denmark)

    Malinov, S.; Böttger, A.J.; Mittemeijer, E.J.

    2001-01-01

    The phase transformations of homogeneous Fe-N alloys of nitrogen contents from 10 to 26 at. pct were investigated by means of X-ray diffraction analysis upon aging in the temperature range from 373 to 473 K. It was found that precipitation of alpha double prime-Fe16N2 below 443 K does not only oc...

  13. Collecting the Missing Piece of the Puzzle: The Wind Temperatures of Arcturus (K2 III) and Aldeberan (K5 III)

    Science.gov (United States)

    Harper, Graham

    2017-08-01

    Unravelling the poorly understood processes that drive mass loss from red giant stars requires that we empirically constrain the intimately coupled momentum and energy balance. Hubble high spectral resolution observations of wind scattered line profiles, from neutral and singly ionized species, have provided measures of wind acceleration, turbulence, terminal speeds, and mass-loss rates. These wind properties inform us about the force-momentum balance, however, the spectra have not yielded measures of the much needed wind temperatures, which constrain the energy balance.We proposed to remedy this omission with STIS E140H observations of the Si III 1206 Ang. resonance emission line for two of the best studied red giants: Arcturus (alpha Boo: K2 III) and Aldebaran (alpha Tau: K5 III), both of which have detailed semi-empirical wind velocity models. The relative optical depths of wind scattered absorption in Si III 1206 Ang., O I 1303 Ang. triplet., C II 1335 Ang., and existing Mg II h & k and Fe II profiles give the wind temperatures through the thermally controlled ionization balance. The new temperature constraints will be used to test existing semi-empirical models by comparision with multi-frequency JVLA radio fluxes, and also to constrain the flux-tube geometry and wave energy spectrum of magnetic wave-driven winds.

  14. High Temperature Electrolysis 4 kW Experiment Design, Operation, and Results

    Energy Technology Data Exchange (ETDEWEB)

    J.E. O' Brien; X. Zhang; K. DeWall; L. Moore-McAteer; G. Tao

    2012-09-01

    This report provides results of long-term stack testing completed in the new high-temperature steam electrolysis multi-kW test facility recently developed at INL. The report includes detailed descriptions of the piping layout, steam generation and delivery system, test fixture, heat recuperation system, hot zone, instrumentation, and operating conditions. This facility has provided a demonstration of high-temperature steam electrolysis operation at the 4 kW scale with advanced cell and stack technology. This successful large-scale demonstration of high-temperature steam electrolysis will help to advance the technology toward near-term commercialization.

  15. Nonlinear reflection of a nanosecond laser pulse from thin aluminum film in the temperature range 2-14 kK

    Science.gov (United States)

    Karabutov, A. A.; Kaptilniy, A. G.; Ksenofontov, D. M.; Makarov, V. A.; Cherepetskaya, E. B.; Podymova, N. B.

    2015-11-01

    This letter aims to experimentally demonstrate the possibility of measuring the temporal dependencies of the surface temperature of an aluminum film confined by a transparent dielectric in the range below and above the critical temperature of aluminum (from 2 kK to 14 kK). Such temperatures are achieved under the action of a powerful linearly-polarized laser pulse of one nanosecond in duration onto the film’s surface. To find the temporal dependencies of the temperature of the aluminum film the nonlinear reflection coefficient of its irradiated surface is measured to determine the radiation of a Q-switched Nd:YAG laser at the fundamental wavelength.

  16. A 13 kA current lead, measuring 1.5 m in length. The lower part consists of a high-temperature superconductor (Bi-2223), operating at between 50 K and 4.5 K, while the heat-exchanger upper part allows the current to be brought from room temperature to 50 K.

    CERN Multimedia

    2004-01-01

    A 13 kA current lead, measuring 1.5 m in length. The lower part consists of a high-temperature superconductor (Bi-2223), operating at between 50 K and 4.5 K, while the heat-exchanger upper part allows the current to be brought from room temperature to 50 K.

  17. Characterisation of net type thermal insulators at 1.8 K low boundary temperature

    CERN Document Server

    Peón-Hernández, G; Szeless, Balázs

    1997-01-01

    The Large Hadron Collider's superconducting magnets are cooled by superfluid helium at 1.8 K and housed in cryostats that minimise the heat inleak to this temperature level by extracting heat at 70 and 5 K. In the first generation of prototype cryostats, the radiative heat to the 1.8 K temperature level accounted for 70 % of the total heat inleak. An alternative to enhance the cryostat thermal performance incorporates a thermalised radiation screen at 5 K. In order to avoid contact between the 5 K radiation screen and the cold mass, insulators are placed between both surfaces. Sets of commercial fibre glass nets are insulator candidates to minimise the heat inleak caused by a accidental contact between the two temperature levels. A model to estimate their performance is presented. A set-up to thermally characterise them has been designed and is also described in the paper. Finally, results as a function of the number of the spacer nets, the boundary temperatures and the compressive force in the spacer are pre...

  18. Shock Tube/Laser Absorption Studies of Jet Fuels at Low Temperatures (600-1200K)

    Science.gov (United States)

    2013-08-27

    fundamental band of CO (4.3–5.8 μm) to find can- didate CO transitions suitable for high-temperature (>1000 K) in situ detection that are isolated ...A systematic line-selection procedure was used to find lines with sufficient absorption strength, isolation from interfering absorption, temperature...the reaction volume, for either exothermic or endo- thermic reactions, also causes the reflected shock environment to deviate from constant-volume

  19. The reactions of OH radicals with chloroalkanes in the temperature range 295-360 K

    DEFF Research Database (Denmark)

    Markert, F.; Nielsen, O.J.

    1992-01-01

    The temperature dependency of the rate constants for the gas phase reaction of OH radicals with a series of chloroalkanes was measured in the temperature range from 295 to 360 K at a total pressure of 1 atm. The rate constants were obtained by using the absolute technique of pulse radiolysis...... combined with kinetic UV spectroscopy. The results are discussed in terms of reactivity trends....

  20. Febrile temperature facilitates hERG/IKr degradation through an altered K(+) dependence.

    Science.gov (United States)

    Zhao, Yan; Wang, Tingzhong; Guo, Jun; Yang, Tonghua; Li, Wentao; Koichopolos, Jennifer; Lamothe, Shawn M; Kang, Yudi; Ma, Aiqun; Zhang, Shetuan

    2016-10-01

    Dysfunction of the rapidly activating delayed rectifier K(+) channel (IKr) encoded by the human ether-à-go-go-related gene (hERG) is the primary cause of acquired long QT syndrome (LQTS). Fever has been reported to trigger LQTS in various conditions. We aim to clarify the effect and underlying mechanisms of febrile temperature on hERG expressed in HEK cells, IKr in neonatal rat ventricular myocytes, and the QT interval in rabbits. Western blot analysis was used to determine the expression of hERG channel protein in stably transfected HEK 293 cells. Immunocytochemistry was used to visualize the localization of hERG channels. The whole-cell patch clamp technique was used to record hERG K(+) current (IhERG) in hERG expressing HEK 293 cells, as well as IKr, transient outward K(+) current (Ito), and L-type Ca(2+) current (ICa) in neonatal rat ventricular myocytes. Electrocardiographic recordings were performed in an in vivo rabbit model. Compared with culture at 37°C, culture at 40°C reduced the mature hERG expression and IhERG in an extracellular K(+) concentration-dependent manner. Point mutations that remove the K(+) dependence of hERG-S624T and F627Y-also abolished the febrile temperature-induced hERG reduction. In neonatal rat ventricular myocytes, febrile temperature prolonged the action potential duration and selectively reduced IKr in a manner similar to low K(+) culture. In an in vivo rabbit model, fever and hypokalemia synergistically prolonged the QT interval. Febrile temperature facilitates the development of LQTS by expediting hERG degradation through altered K(+) dependence. Copyright © 2016 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

  1. Thermodynamic constants of N-[tris(hydroxymethyl)methyl-3-amino]propanesulfonic acid (Taps) from the temperatures 278.15 K to 328.15 K

    Energy Technology Data Exchange (ETDEWEB)

    Roy, Rabindra N. [Walter H. Hoffman Department of Chemistry, Drury University, 900 N. Benton Avenue, Springfield, MO 65802 (United States)]. E-mail: rroy@drury.edu; Roy, Lakshmi N. [Walter H. Hoffman Department of Chemistry, Drury University, 900 N. Benton Avenue, Springfield, MO 65802 (United States); LeNoue, Sean R. [Walter H. Hoffman Department of Chemistry, Drury University, 900 N. Benton Avenue, Springfield, MO 65802 (United States); Denton, Cole E. [Walter H. Hoffman Department of Chemistry, Drury University, 900 N. Benton Avenue, Springfield, MO 65802 (United States); Simon, Ashley N. [Walter H. Hoffman Department of Chemistry, Drury University, 900 N. Benton Avenue, Springfield, MO 65802 (United States); Richards, Sarah J. [Walter H. Hoffman Department of Chemistry, Drury University, 900 N. Benton Avenue, Springfield, MO 65802 (United States); Moore, Andrew C. [Walter H. Hoffman Department of Chemistry, Drury University, 900 N. Benton Avenue, Springfield, MO 65802 (United States); Roy, Chandra N. [Walter H. Hoffman Department of Chemistry, Drury University, 900 N. Benton Avenue, Springfield, MO 65802 (United States); Redmond, R. Ryan [Walter H. Hoffman Department of Chemistry, Drury University, 900 N. Benton Avenue, Springfield, MO 65802 (United States); Bryant, Paul A. [Walter H. Hoffman Department of Chemistry, Drury University, 900 N. Benton Avenue, Springfield, MO 65802 (United States)

    2006-04-15

    Values of the second thermodynamic dissociation constant pK{sub 2} of N-[tris(hydroxymethyl)methyl-3-amino]propanesulfonic acid (Taps) have been determined at twelve temperatures from 278.15 K to 328.15 K including 310.15 K by measurements of the electromotive-force for cells without liquid junction of the type: Pt|H{sub 2} (g, p{sup -}bar =101.325 kPa)|Taps (m{sub 1}), NaTapsate (m{sub 2}), NaCl (m{sub 3})|AgCl|Ag, where m denotes molality. The pK{sub 2} values for the dissociation of Taps are represented by the equation: pK{sub 2}=2969.61.(K/T) - 17.05052+2.73697.ln(T/K). The values of pK{sub 2} for Taps were found to be (8.502+/-0.0007) at T=298.15 K and (8.225+/-0.0009) at T=310.15 K, respectively, indicating thereby to be useful as buffer solutions for pH control in the region 7.4 to 8.5. The thermodynamic quantities, {delta}G{sup -}bar , {delta}H{sup -}bar , {delta}S{sup -}bar , and {delta}C{sub p}{sup -}bar dissociation process of Taps have been derived from the temperature coefficients of the pK{sub 2}.

  2. Variable- and fixed-point blackbody sources developed at VNIIOFI for precision measurements in radiometry and thermometry within 100K-3500K temperature range

    Science.gov (United States)

    Sapritsky, V. I.; Khlevnoy, B. B.; Ogarev, S. A.; Privalsky, V. E.; Samoylov, M. L.; Sakharov, M. K.; Bourdakin, A. A.; Panfilov, A. S.

    2006-09-01

    The demands of modern radiation thermometry and radiometry are being satisfied by a large variety of high-precision unique BB sources (both fixed-point and variable temperature) designed for a wide range of temperature from 100 K to 3500 K. The paper contains a detailed review of low-, medium- and high-temperature precision blackbodies developed at VNIIOFI as the basis of the spectral radiance and irradiance calibration devices in the rank of National standards. The blackbodies include: 1) variable-temperature (100K..1000K) research-grade extended-area (up to 100 mm) models intended to perform radiometric calibrations by comparison with a primary standard source, as well as can be used as the sources for high-accuracy IR calibration of space-borne and other systems not requiring a vacuum environment; 2) low-temperature fixed-point blackbodies on the basis of phase transitions of pure metals such as In and Ga sources, and the metal-metal eutectics operating within the medium-temperature range (300K to 400K); these are used for pyrometric measurements, IR-radiometry, preflight and (future aspects) in-flight calibration of space borne IR instruments; 3) high-temperature wide aperture variable-temperature blackbodies (1800K to 3500K) such as BB3500MP, BB3500YY designed and fabricated, along with fixed-point cells working above the ITS-90 temperatures on the basis of phase transitions of metal-carbon eutectic alloys (Re-C, TiC-C, ZrC-C, HfC-C), which possess unique reproducibility of 0.1% or less.

  3. Thermal Stability of Austempered Ductile Iron Evaluated in a Temperature Range of 20-300K

    Directory of Open Access Journals (Sweden)

    Dawid MYSZKA

    2016-05-01

    Full Text Available The aim of this article was to determine through changes in magnetic properties the stability of the austempered ductile iron (ADI microstructure during temperature changes in a range of 20 – 300 K. The measurements were taken in a vibrating sample magnetometer (VSM using Fe27Ni2TiMoAlNb austenitic stainless steel and four types of austempered ductile iron obtained under various heat treatment conditions. The plotted curves showing changes in the magnetisation degree as a function of temperature had a number of characteristic points illustrating changes taking place in the microstructure. For each of the materials examined, the martensite start temperature Ms and the temperature range within which the martensitic transformation takes place were identified.

  4. Absolute rate constant and O(3P yield for the O(1D+N2O reaction in the temperature range 227 K to 719 K

    Directory of Open Access Journals (Sweden)

    S. A. Carl

    2008-10-01

    Full Text Available The absolute rate constant for the reaction that is the major source of stratospheric NOx, O(1D+N2O → products, has been determined in the temperature range 227 K to 719 K, and, in the temperature range 248 K to 600 K, the fraction of the reaction that yields O(3P. Both the rate constants and product yields were determined using a recently-developed chemiluminescence technique for monitoring O(1D that allows for higher precision determinations for both rate constants, and, particularly, O(3P yields, than do other methods. We found the rate constant, kR1, to be essentially independent of temperature between 400 K and 227 K, having a value of (1.37±0.11×10−10 cm3 s−1, and for temperatures greater than 450 K a marked decrease in rate constant was observed, with a rate constant of only (0.94±0.11×10−10 cm3 s−1 at 719 K. The rate constants determined over the 227 K–400 K range show very low scatter and are significantly greater, by 20% at room temperature and 15% at 227 K, than the current recommended values. The fraction of O(3P produced in this reaction was determined to be 0.002±0.002 at 250 K rising steadily to 0.010±0.004 at 600 K, thus the channel producing O(3P can be entirely neglected in atmospheric kinetic modeling calculations. A further result of this study is an expression of the relative quantum yields as a function of temperature for the chemiluminescence reactions (kCL1C2H + O(1D → CH(A + CO and (kCL2C2H + O(3P → CH(A + CO, both followed by CH(A → CH(X + hν, as kCL1(T/kCL2(T=(32.8T−3050/(6.29T+398.

  5. Electrothermally Tunable Graphene Resonators Operating at Very High Temperature up to 1200 K.

    Science.gov (United States)

    Ye, Fan; Lee, Jaesung; Feng, Philip X-L

    2018-02-23

    The unique negative thermal expansion coefficient and remarkable thermal stability of graphene make it an ideal candidate for nanoelectromechanical systems (NEMS) with electrothermal tuning. We report on the first experimental demonstration of electrothermally tuned single- and few-layer graphene NEMS resonators operating in the high frequency (HF) and very high frequency (VHF) bands. In single-, bi-, and trilayer (1L, 2L, and 3L) graphene resonators with carefully controlled Joule heating, we have demonstrated remarkably broad frequency tuning up to Δf/f 0 ≈ 310%. Simultaneously, device temperature variations imposed by Joule heating are monitored using Raman spectroscopy; we find that the device temperature increases from 300 K up to 1200 K, which is the highest operating temperature known to date for electromechanical resonators. Using the measured frequency and temperature variations, we further extract both thermal expansion coefficients and thermal conductivities of these devices. Comparison with graphene electrostatic gate tuning indicates that electrothermal tuning is more efficient. The results clearly suggest that the unique negative thermal expansion coefficient of graphene and its excellent tolerance to very high temperature can be exploited for engineering highly tunable and robust graphene transducers for harsh and extreme environments.

  6. Laser Cooling of a Solid by 16K Starting from Room Temperature

    Energy Technology Data Exchange (ETDEWEB)

    Mungan, C.; Buchwald, M.; Edwards, B.; Epstein, R.; Gosnell, T. [Los Alamos National Laboratory, Mail Stop E543, Los Alamos, New Mexico 87545 (United States)

    1997-02-01

    An Yb{sup 3+}-doped optical fiber is laser cooled {ital in vacuo}from 298 to 282K. Cooling results from anti-Stokes fluorescence of the ytterbium ions after optical pumping at a wavelength of 1015nm. The sample temperature is deduced from the emission spectrum, which is sensitive to the populations in the excited-state multiplet of the ions. The temperature change is limited by the coupling between the fiber and ambient blackbody radiation, as confirmed when samples suddenly exposed to the pump laser are found to exponentially relax towards thermal steady state with the expected time constants. {copyright} {ital 1997} {ital The American Physical Society}

  7. K-Based Geopolymer from metakaolin: roles of K/Al ratio and water or steam Curing at different temperatures

    Directory of Open Access Journals (Sweden)

    Tawfik, A.

    2016-06-01

    Full Text Available K-based geopolymer binder was prepared by reacting metakaolin with alkaline solutions having different potassium contents and by water curing at room temperature and 80 °C as well as steam curing at 150 and 180 °C. The phase formation, microstructure and Al and Si nearest neighbor environments were studied using XRD, TEM and 27Al and 29Si MAS NMR spectroscopy, respectively. The results revealed that amorphous alumino-silicates were predominant in geopolymer prepared by curing up to 28 days at room temperature or at 80 °C. The amorphous alumino-silicates persisted after hydrothermal treatment at 150 °C/48 hrs and even at 180 °C/30 hrs. However, the samples cured hydrothermally at 180 °C/48 hrs revealed formation of crystalline potassium aluminum silicate and chabazite phases. The Al nearest neighbor environments was not significantly affected by increasing the K/Al ratio up to 1.55 or by the curing temperatures. On the other hand, the geopolymer reaction appears to have increased when cured at 80 °C or steam cured at 150° and 180 °C and crystalline aluminosilicates resulted when the geopolymer sample was hydrothermally treated at 180 °C/48 hrs.Se prepararon geopolímeros por reacción de metacaolín con disoluciones alcalinas con diferentes contenidos de potasio. Se realizó un curado con agua a temperatura ambiente y a 80 °C, y con vapor de agua a 150 y 180 °C. La formación de las diferentes fases así como la microestructura y entornos del Al y Si se estudiaron mediante DRX, TEM y espectroscopia de RMN MAS de 27Al y 29Si. Los aluminosilicatos amorfos fueron predominantes en aquellos geopolímeros sometidos a curado de hasta 28 días a temperatura ambiente o a 80 °C. Los aluminosilicatos amorfos persistieron tras el tratamiento hidrotermal a 150 °C/48 horas e incluso a 180 °C/30 h. Sin embargo, las muestras curadas hidrotermalmente a 180 °C/48 h revelaron la formación de fases cristalinas de silicatos de aluminio y potasio, as

  8. K-band spectroscopic metallicities and temperatures of M-dwarf stars

    Directory of Open Access Journals (Sweden)

    Rojas-Ayala Bárbara

    2013-04-01

    Full Text Available I present the metallicity and effective temperature techniques developed for M dwarf stars by Rojas-Ayala et al. (2010, 2012. These techniques are based on absorption features present in the modest resolution K-band spectra (R∼2700 of M dwarfs and have been calibrated using FGK+M dwarf pairs and synthetic atmosphere models. The H2O-K2 index seems to overestimate the effective temperatures of M dwarfs when compared to interferometric measurements. The metallicity distribution of the M dwarf host candidates by the Kepler Mission hints that jovian-size planets form preferentially around solar and super-solar metallicity environments, while small rocky planet host exhibit a wide range of metallicities, just like in their solar-type counterparts.

  9. Time resolved quantitative imaging of charring in materials at temperatures above 1000 K

    Science.gov (United States)

    Böhrk, Hannah; Jemmali, Raouf

    2016-07-01

    A device is presented allowing for in situ investigation of chemically changing materials by means of X-ray imaging. A representative cork ablator sample, additionally instrumented with thermocouples, is encapsulated in an evacuated cell heating a sample surface with a heat flux of 230 kW/m2. The images show the sample surface and the in-depth progression of the char front dividing the char layer from the virgin material. Correlating the images to thermocouple data allows for the deduction of a reaction temperature. For the representative cork ablator investigated at the present conditions, the progression rate of the pyrolysis layer is determined to 0.0285 mm/s and pyrolysis temperature is 770 or 737 K, depending on the pre-existing conditions. It is found that the novel device is ideally suited for volume process imaging.

  10. Design of a 100 kVA high temperature superconducting demonstration synchronous generator

    Science.gov (United States)

    Al-Mosawi, M. K.; Beduz, C.; Goddard, K.; Sykulski, J. K.; Yang, Y.; Xu, B.; Ship, K. S.; Stoll, R.; Stephen, N. G.

    2002-08-01

    The paper presents the main features of a 100 kVA high temperature superconducting (HTS) demonstrator generator, which is designed and being built at the University of Southampton. The generator is a 2-pole synchronous machine with a conventional 3-phase stator and a HTS rotor operating in the temperature range 57-77 K using either liquid nitrogen down to 65 K or liquid air down to 57 K. Liquid air has not been used before in the refrigeration of HTS devices but has recently been commercialised by BOC as a safe alternative to nitrogen for use in freezing of food. The generator will use an existing stator with a bore of 330 mm. The rotor is designed with a magnetic core (invar) to reduce the magnetising current and the field in the coils. For ease of manufacture, a hybrid salient pole construction is used, and the superconducting winding consists of twelve 50-turn identical flat coils. Magnetic invar rings will be used between adjacent HTS coils of the winding to divert the normal component of the magnetic field away from the Bi2223 superconducting tapes. To avoid excessive eddy-current losses in the rotor pole faces, a cold copper screen will be placed around the rotor core to exclude ac magnetic fields.

  11. Test results of full-scale high temperature superconductors cable models destined for a 36 kV, 2 kA(rms) utility demonstration

    DEFF Research Database (Denmark)

    Daumling, M.; Rasmussen, C.N.; Hansen, F.

    2001-01-01

    with thermal terminations, an HTS cable conductor including a flexible thermal insulation, a conventional room temperature dielectric, and a closed-loop circulating cooling system maintaining the temperature between 68 and 78 K. Critical issues before the commercialisation of this technology...... are the improvement of the thermal insulation, and the reduction of costs. (C) 2001 Elsevier Science B.V. All rights reserved....

  12. Development of the active magnetic regenerative refrigerator operating between 77 K and 20 K with the conduction cooled high temperature superconducting magnet

    Science.gov (United States)

    Park, Inmyong; Jeong, Sangkwon

    2017-12-01

    The experimental investigation of an active magnetic regenerative refrigerator (AMRR) operating between 77 K and 20 K is discussed in this paper, with detailed energy transfer analysis. A multi-layered active magnetic regenerator (AMR) is used, which consists of four different rare earth intermetallic compounds in the form of irregular powder. Numerical simulation confirms that the AMR can attain its target operating temperature range. Magnetic field alternation throughout the AMR is generated by a high temperature superconducting (HTS) magnet. The HTS magnet is cooled by a two stage Gifford-McMahon (GM) cryocooler. Helium gas was employed as a working fluid and its oscillating flow in the AMR is controlled in accordance with the magnetic field variation. The AMR is divided into two stages and each stage has a different mass flow rate as needed to achieve the desired cooling performance. The temperature variation of the AMR during the experiment is monitored by temperature sensors installed inside the AMR. The experimental results show that the AMRR is capable of achieving no-load temperature of 25.4 K while the warm end temperature is 77 K. The performance of the AMRR is analyzed by observing internal temperature variations at cyclic steady state. Furthermore, numerical estimation of the cooling capacity and the temperature variation of the AMR are examined and compared with the experimental results.

  13. Investigations of Heat Transfer in Vacuum between Room Temperature and 80 K

    Science.gov (United States)

    Hooks, J.; Demko, J. A.; E Fesmire, J.; Matsumoto, T.

    2017-12-01

    The heat transfer between room temperature and 80 K is controlled using various insulating material combinations. The modes of heat transfer are well established to be conduction and thermal radiation when in a vacuum. Multi-Layer Insulation (MLI) in a vacuum has long been the best approach. Typically this layered system is applied to the cold surface. This paper investigates the application of MLI to both the cold and warm surface to see whether there is a significant difference. In addition if MLI is on the warm surface, the cold side of the MLI may be below the critical temperature of some high temperature superconducting (HTS) materials. It has been proposed that HTS materials can serve to block thermal radiation. An experiment is conducted to measure this effect. Boil-off calorimetry is the method of measuring the heat transfer.

  14. Differential protein expression following low temperature culture of suspension CHO-K1 cells

    Directory of Open Access Journals (Sweden)

    Henry Michael

    2008-04-01

    Full Text Available Abstract Background To ensure maximal productivity of recombinant proteins (rP during production culture it is typical to encourage an initial phase of rapid cell proliferation to achieve high biomass followed by a stationary phase where cellular energies are directed towards production of rP. During many such biphasic cultures, the initial phase of rapid cell growth at 37°C is followed by a growth arrest phase induced through reduction of the culture temperature. Low temperature induced growth arrest is associated with many positive phenotypes including increased productivity, sustained viability and an extended production phase, although the mechanisms regulating these phenotypes during mild hypothermia are poorly understood. Results In this study differential protein expression in suspension CHO-K1 cells was investigated following a reduction of the culture temperature from 37°C to 31°C in comparison to standard batch culture maintained at 37°C using 2D-DIGE (Fluorescence 2-D Difference Gel Electrophoresis and mass spectrometry (MS. There is only limited proteomic analysis of suspension-grown CHO cells describing a direct comparison of temperature shifted versus non-temperature shifted cultures using 2D-DIGE. This investigation has enabled the identification of temperature-dependent as well as temperature-independent proteomic changes. 201 proteins were observed as differentially expressed following temperature shift, of which 118 were up regulated. Of the 53 proteins identified by MALDI-ToF MS, 23 were specifically differentially expressed upon reduction of the culture temperature and were found related to a variety of cellular functions such as regulation of growth (HNRPC, cap-independent translation (EIF4A, apoptosis (importin-α, the cytoskeleton (vimentin and glycoprotein quality control (alpha glucosidase 2. Conclusion These results indicate the extent of the temperature response in CHO-K1 cells and suggest a number of key

  15. Determination of the Thermal Diffusivity of Electrically Non-Conductive Solids in the Temperature Range from 80 K to 300 K by Laser-Flash Measurement

    Science.gov (United States)

    Hemberger, F.; Göbel, A.; Ebert, H.-P.

    2010-12-01

    The adoption of the popular laser-flash method at temperatures far below 300 K is restricted by the weak signal-to-noise ratio and the limited spectral bandwidth of the commonly used mercury cadmium tellurite (MCT) infrared (IR) detector used as a non-contacting temperature probe. In this work, a different approach to measure the temperature rise in pulse heating experiments is described and evaluated. This method utilizes the change of the temperature-dependent electrical resistance of a thin strip of sputtered gold for the detection of a temperature rise as it was proposed by Kogure et al. The main advantage of this method at lower temperatures is the significantly higher signal-to-noise ratio compared to the commonly used IR detectors. A newly developed laser-flash apparatus using this detection method for the determination of the thermal diffusivity in the temperature range from 80 K to 300 K is presented. To test the accuracy of the new detection method, the thermal diffusivity of a borosilicate crown glass (BK7) specimen at 300 K was determined and compared to results derived with a MCT detector. Good agreement of the derived thermal diffusivity values within 3 % was found. The thermal diffusivity of BK7 and polycrystalline aluminum nitride (AlN) was measured at temperatures between 80 K and 300 K by a laser-flash method to test the functionality of the apparatus. Finally, the thermal conductivity was calculated using values for the specific heat capacity determined by temperature modulated differential scanning calorimetry (MDSC). Comparisons with literature data confirm the reliability of the experimental setup.

  16. Experimental Reconstructions of Surface Temperature using the PAGES 2k Network

    Science.gov (United States)

    Wang, Jianghao; Emile-Geay, Julien; Vaccaro, Adam; Guillot, Dominique; Rajaratnam, Bala

    2014-05-01

    Climate field reconstructions (CFRs) of the Common Era provide uniquely detailed characterizations of natural, low-frequency climate variability beyond the instrumental era. However, the accuracy and robustness of global-scale CFRs remains an open question. For instance, Wang et al. (2013) showed that CFRs are greatly method-dependent, highlighting the danger of forming dynamical interpretations based on a single reconstruction (e.g. Mann et al., 2009). This study will present a set of new reconstructions of global surface temperature and compare them with existing reconstructions from the IPCC AR5. The reconstructions are derived using the PAGES 2k network, which is composed of 501 high-resolution temperature-sensitive proxies from eight continental-scale regions (PAGES2K Consortium, 2013). Four CFR techniques are used to produce reconstructions, including RegEM-TTLS, the Mann et al. (2009) implementation of RegEM-TTLS (hereinafter M09-TTLS), CCA (Smerdon et al., 2010) and GraphEM (Guillot et al., submitted). First, we show that CFRs derived from the PAGES 2k network exhibit greater inter-method similarities than the same methods applied to the proxy network of Mann et al. (2009) (hereinafter M09 network). For instance, reconstructed NH mean temperature series using the PAGES 2k network are in better agreement over the last millennium than the M09-based reconstructions. Remarkably, for the reconstructed temperature difference between the Medieval Climate Anomaly and the Little Ice Age, the spatial patterns of the M09-based reconstructions are greatly divergent amongst methods. On the other hand, not a single PAGES 2k-based CFR displays the La Niña-like pattern found in Mann et al. (2009); rather, no systematic pattern emerges between the two epochs. Next, we quantify uncertainties associated with the PAGES 2k-based CFRs via ensemble methods, and show that GraphEM and CCA are less sensitive to random noise than RegEM-TTLS and M09-TTLS, consistent with pseudoproxy

  17. Gas gun driven dynamic fracture and fragmentation of Ti-6Al-4V cylinders at initial temperatures between 150 K and 750 K

    Science.gov (United States)

    Jones, David R.; Chapman, David J.; Eakins, Daniel E.

    2017-01-01

    We present a study on the dynamic fracture and fragmentation of Ti-6Al-4V cylinders at initial temperatures ranging from approximately 150 K to 750 K. Cylinders with an inner diameter of 50 mm and a wall thickness of 4 mm were driven into uniform axially-symmetric expansion at radial strain rates of 104 s-1 using the ogive-insert gas gun method. Diagnostics consisted of simultaneous high speed imaging and multiple points of laser velocimetry (PDV) along the length of the sample. The imaging and PDV provided a record of the expansion process, giving expansion velocity and the failure strain. Recovered fragments were examined with optical and scanning electron microscopy and electron backscatter diffraction techniques to determine the fracture mechanisms for each initial temperature. The failure strain (radial strain at first fracture) was observed to increase with temperature over the range tested, from 7.4 ± 5.2 percent at 158 K to 24.1 ± 2.4 percent at 724 K. In experiments from 158 K up to 609 K the fracture mechanism was found to be ductile tearing under mode II loading along the planes of maximum shear at 45° to the radius. At an initial cylinder temperature of 724 K the fracture mechanism transitioned to void nucleation and coalescence along adiabatic shear bands, again forming at 45° to the radial direction. The fragmentation toughness Kf was observed to also increase with temperature until the 724 K shot where there was a marked reduction, suggesting the formation of shear bands at high temperatures reduced the energy required to form fragments. The average value of Kf was 101 ± 13 MPa m1/2.

  18. Study of the Effects of Temperature and Pressure on the Thermodynamic and Acoustic Properties of 2-Methyl-1-butanol at Temperatures from 293K to 318K and Pressures up to 100MPa

    Science.gov (United States)

    Dzida, Marzena

    2010-01-01

    The speeds of sound in 2-methyl-1-butanol were measured at temperatures from 293K to 318K and pressures up to 101MPa. The densities were measured in the same temperature range under atmospheric pressure. The isobaric specific heat capacities were measured at atmospheric pressure and temperatures from 284K to 355K. The densities, isobaric heat capacities, isobaric thermal expansions, isentropic compressibilities, isothermal compressibilities, and internal pressures as functions of temperature and pressure were calculated using the experimental speeds of sound under elevated pressures together with the densities and heat capacities at atmospheric pressure. The effects of temperature and pressure on the isobaric thermal expansion and internal pressure of 2-methyl-1-butanol are discussed and compared with those of pentan-1-ol, 2-methyl-2-butanol, and pentan-3-ol.

  19. Temperature-dependent activation energy of electromigration in Cu/porous low-k interconnects

    Science.gov (United States)

    Zheng, Hui; Yin, Binfeng; Zhou, Ke; Chen, Leigang; Kuo, Chinte

    2017-08-01

    In this paper, it was reported that the Time-to-Failure (TTF) of electromigration (EM) in Cu/porous low-k interconnects deviated from the classical Black's Equation at 250-350 °C due to moisture invasion. The EM activation energy (Ea) was 1.003 eV at above 300 °C, whereas the apparent value reduced to be negative below 300 °C, being accompanied by significantly narrowed TTF distribution. The corresponding change in the failure mode was distinctly revealed, which indicated that the oxidation of Ta-based liner due to moisture invasion through the porous low-k contributed significantly and modestly to the EM failure below and above 300 °C. The mechanism of the liner oxidation was interpreted with the theory of field-assisted cation migration, which suggested the steep slowdown of the oxidation from 275 to 300 °C could be ascribed to the substantial decrease in the moisture concentration at the low-k/Ta oxide interface, most probably owing to significant suppression of adsorption and surface diffusion of chemisorbed moisture in the nanoporous low-k. The inconsistent EM behaviors at the lower and higher temperatures were thus interpreted by the competition of intrinsic and extrinsic EM controlled separately by Cu diffusion along the Cu/SiN-based cap layer interface and the moisture-damaged Cu/Ta interface.

  20. Measurement of the primary phodesorption yield at 4.2 K, 77 K and room temperature in a quasi-closed geometry

    CERN Document Server

    Baglin, V

    1996-01-01

    In the context of the Large Hadron Collider project, the normal incidence photodesorption yield of neutral gases from a stainless steel surface has been measured at 4.2 K, 77 K and room temperature. The yields were measured using a synchrotron radiation photon beam with a critical energy of 45.3 eV, which is very near that to be expected in the LHC. It has been shown that the primary photodesorption yield decrease with decreasing temperature. The gases desorbed were H2, CH4, CO and CO2. At 4.2 K and 77 K the H2O primary photodesorption yield was practically zero. At room temperature the primary photodesorption yields were 5 10-4, 1.6 10-5, 2.5 10-4 and 2.2 10-4 molecules photon-1 respectively for H2, CH4, CO and CO2. At 77 K the primary photodesorption yields of H2, CH4, CO and CO2 were reduced by factors of 2, 4, 17 and 32 respectively with respect to room temperature. At 4.2 K, these corresponding reduction factors were 14, 20, 42 and 31.

  1. Monitoring Excitations of the N =1 Landau Level by Optical Emission at mK Temperatures

    Science.gov (United States)

    Levy, Antonio; Wurstbauer, Ursula; Fields, Dov; Pinczuk, Aron; Watson, John; Mondal, Sumit; Manfra, Michael J.; West, Ken W.; Pfeiffer, Loren N.

    2013-03-01

    Optical emission experiments have proven to be powerful contactless probe of collective states of electrons in the second (N =1) Landau Level (LL). We report the emission spectrum from optical recombination in the N =0 and N =1 LL's the second LL. The 2DEG is confined in ultra-high-mobility GaAs quantum well structures. Optical emission red-shifted from the main luminescence of the N =0 and N =1 LL are interpreted as shakeup processes of quasiparticles in the N =1 LL. Results of two samples with different carrier densities measured in the temperature range of 42mK mK will be compared. The experimental observations will be discussed taking into account the striking quantum phases dominating the second LL. Supported by NSF and AvH

  2. Damage and etching of ultra low-k materials in fluorocarbon plasma at lowered temperatures

    Science.gov (United States)

    Lopaev, D. V.; Mankelevich, Yu A.; Rakhimova, T. V.; Zotovich, A. I.; Zyryanov, S. M.; Baklanov, M. R.

    2017-12-01

    SiOCH ULK films with k-value from 2.5 to 2.1 and porosity from 24 to 40% were etched in CHF3, CHF3  +  Ar, CF4 and CF4  +  Ar plasmas at  +15…‑120 °C with and without bias being applied. It was shown that the presence of Ar in gas mixture can significantly increase the damage of unetched ultra low-k (ULK) material (at sidewalls) due to the removal of  ‑CH3 groups from the film by VUV photons. It was also shown that etching and damage of the sidewalls by F atoms can be partially prevented by lowering the temperature of the sample.

  3. A sensitive time-resolved radiation pyrometer for shock-temperature measurements above 1500 K

    Science.gov (United States)

    Boslough, Mark B.; Ahrens, Thomas J.

    1989-01-01

    The general design, calibration, and performance of a new high-sensitivity radiation pyrometer are described. The pyrometer can determine time-resolved temperatures (as low as 1500 K) in shocked materials by measuring the spectral radiance of light emitted from shocked solid samples in the visible and near-infrared wavelength range (0.5-1.0 micron). The high sensitivity of the radiation pyrometer is attributed to the large angular aperture (0.06 sr), the large bandwidth per channel (up to 0.1 micron), the large photodiode detection areas (1.0 sq cm), and the small number of calibrated channels (4) among which light is divided.

  4. (Vapour + liquid) equilibria of (fluoromethane + tetrafluoromethane) at the temperature 130.46 K

    OpenAIRE

    Fonseca, I. M. A.; Sardinha, G. G.; Lobo, Lélio Q.

    1998-01-01

    The total vapour pressure of binary liquid mixtures of (fluoromethane+tetrafluoromethane) has been measured at the temperature 130.46 K. Two partially miscible liquid phases were found. The excess molar Gibbs energy was calculated in the region where the two liquids are mutually soluble. For the hypothetical equimolar mixture,GEm01 (x=0.5)=846 Jmol-1. http://www.sciencedirect.com/science/article/B6WHM-45J58FM-1B/1/78724d9c4f932fc881a978011fc1d879

  5. Electron Temperature Measurement of Buried Layer Targets Using Time Resolved K-shell Spectroscopy

    Science.gov (United States)

    Marley, Edward; Foord, M. E.; Shepherd, R.; Beiersdorfer, P.; Brown, G.; Chen, H.; Emig, J.; Schneider, M.; Widmann, K.; Scott, H.; London, R.; Martin, M.; Wilson, B.; Iglesias, C.; Mauche, C.; Whitley, H.; Nilsen, J.; Hoarty, D.; James, S.; Brown, C. R. D.; Hill, M.; Allan, P.; Hobbs, L.

    2016-10-01

    Short pulse laser-heated buried layer experiments have been performed with the goal of creating plasmas with mass densities >= 1 g/cm3 and electron temperatures >= 500 eV. The buried layer geometry has the advantage of rapid energy deposition before significant hydrodynamic expansion occurs. For brief periods (< 40 ps) this provides a low gradient, high density platform for studying emission characteristics under extreme plasma conditions. A study of plasma conditions achievable using the Orion laser facility has been performed. Time resolved K-shell spectroscopy was used to determine the temperature evolution of buried layer aluminum foil targets. The measured evolution is compared to a 2-D PIC simulation done using LSP, which shows late time heating from the non-thermal electron population. This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.

  6. The Temperature Dependence of the Resistivity the Noble Metals from 0.03 to 9 K.

    Science.gov (United States)

    Steenwyk, Steven Dale

    We present here a thorough investigation of the temperature dependent resistivity (rho)(T) of the noble metals for temperatures from 0.3 K - 9 K. We experimentally determine the magnitude of electron-electron scattering contributions as well as the magnitude and mathematical form of the phonon contribution and its variation with strain and impurity content. We review the basics of the relevant theory including some of the recent calculations of the contribution from various scattering mechanisms, specifically, scattering of electrons by other electrons and by phonons. We consider at length the fundamental effects of the dominant contributors to the residual resistivity, impurity and dislocation scattering, in light of the anisotropy in k-space of the relaxation time determined by these mechanisms. We performed measurements of the resistivity to a precision of one ppm on samples ranging from extremely pure single crystals of Cu and Ag to dilute polycrystalline alloys of Cu with Ag. The techniques required to prepare such samples and to make very high precision measurements are discussed. In particular, treatment is given to some of the unique problems faced in using a SQUID based measuring system on samples of nano-ohm resistance with special attention paid to the use of superconducting chokes and transformers to control the electrical response time of the circuit. The results of our measurements give substantial verification of the calculations of the e-e scattering contribution to (rho)(T). Of special interest is the serendipitious verification of the theory of Bermann, Kaveh and Wiser('(DAG)) explaining the origin of the T('4) behavior we had observed in the earliest work. This theory reproduces a nearly T('4) behavior by a combination of electron-electron and electron-phonon scattering. Our data fit their equations very well. While we expected to find, and indeed did find, the effect of dislocation to be a reduction in the phonon scattering, we did not

  7. Sample environment for neutron scattering measurements of internal stresses in engineering materials in the temperature range of 6 K to 300 K.

    Science.gov (United States)

    Kirichek, O; Timms, J D; Kelleher, J F; Down, R B E; Offer, C D; Kabra, S; Zhang, S Y

    2017-02-01

    Internal stresses in materials have a considerable effect on material properties including strength, fracture toughness, and fatigue resistance. The ENGIN-X beamline is an engineering science facility at ISIS optimized for the measurement of strain and stress using the atomic lattice planes as a strain gauge. Nowadays, the rapidly rising interest in the mechanical properties of engineering materials at low temperatures has been stimulated by the dynamic development of the cryogenic industry and the advanced applications of the superconductor technology. Here we present the design and discuss the test results of a new cryogenic sample environment system for neutron scattering measurements of internal stresses in engineering materials under a load of up to 100 kN and in the temperature range of 6 K to 300 K. Complete cooling of the system starting from the room temperature down to the base temperature takes around 90 min. Understanding of internal stresses in engineering materials at cryogenic temperatures is vital for the modelling and designing of cutting-edge superconducting magnets and other superconductor based applications.

  8. Vaporization of graphite in the temperature range of 4000 to 4500 K

    Science.gov (United States)

    Lundell, J. H.; Dickey, R. R.

    1976-01-01

    The vaporization of graphite under intense laser radiation is considered both theoretically and experimentally. Under intense radiation, the mass-loss rate can be high enough to cause the flow in the laser plume to be supersonic. It is shown that under these conditions the vaporization process is coupled to the plume gasdynamics and the mass-loss rate for graphite is 62% of the free vaporization rate. Experimental results are presented for surface temperatures from 3985 to 4555 K and mass-loss rates from 0.56 to 27.0 g per sq cm sec. The results are used to determine the vapor pressure of graphite in a pressure range of 2 to 11 atm, and the values are shown to be in agreement with the JANAF vapor pressure curve.

  9. Radiative Vaporization of Graphite in the Temperature Range of 4000 to 4500 deg K

    Science.gov (United States)

    Lundell, John H.; Dickey, Robert R.

    1976-01-01

    The vaporization of graphite under intense laser radiation is considered both theoretically and experimentally. Under intense radiation, the mass-loss rate can be high enough to cause the flow in the laser plume to be supersonic. Under these conditions, the vaporization process is coupled to the plume gasdynamics. Experimental results are presented for surface temperatures of 3985 to 4555 K and mass-loss rates from 0.52 to 27.0 g/sq cm sec. The data are used to determine the vapor pressure of graphite in a range of 2 to 11 atm, and the results are shown to be in good agreement with the JANAF vapor pressure curve, if the vaporization coefficients are unity. The assumption of unity vaporization coefficients is shown to be reasonable by a comparison of the present results with other recent vapor pressure results for graphite.

  10. Oxide particle coarsening at temperature over 1473K in 9CrODS steel

    Directory of Open Access Journals (Sweden)

    N. Oono

    2016-12-01

    Full Text Available The oxide particle coarsening was evaluated at temperature over 1473K by means of transmission electron microscopy (TEM. After annealing of the 9CrODS extruded bar, the size of oxide particles increases while the number density decreases, indicating that the oxide particles coarsen through Ostwald ripening. The growth rate of the oxide particles follows the fifth-power law, which is in the region of dislocation ‘pipe’ diffusion. The activation energy for pipe diffusion, however, was remarkably high, derived as 891KJ/mole. The stability of oxide particles and the difference of the diffusion velocity in between bcc-δ phase and fcc-γ phase should be considered as the contributions to the activation energy.

  11. Josephson STM at mK temperatures: Coupling to the electronic environment

    Science.gov (United States)

    Dreyer, Michael; Dana, Rami; Liao, Wan-Ting; Lobb, Cris; Wellstood, Fred; Anderson, Bob

    Ultra-small Josephson junctions can couple to modes in the electronic environment. This leads to sub-gap peaks in the I(V) curve in addition to the phase diffuse supercurrent. The I(V) curve can - in principle - be explained by P(E) theory which describes the probability of tunneling at energy E. A recent study showed that antenna modes of the STM tips could be responsible for the observed sideband structures. In our case the explanation appears to be less simple. We employ a dual tip STM at a temperature of 30 mK. The I(V) spectra of the two tips show distinct patterns with only one shared mode. While the supercurrent branch for the ''inner'' tip is visible, it is obscured by a resonance for the ``outer'' tip. Possible causes and applications to other systems will be discussed. Support from NSF (DMR- 0605763) and Laboratory for Physical Sciences.

  12. Thermodynamic properties of spin-polarized 3He gas in the temperature range 1 mK-4 K from the quantum second virial coefficient

    Science.gov (United States)

    Al-Maaitah, A. F.; Sandouqa, A. S.; Joudeh, B. R.; Ghassib, H. B.

    2017-11-01

    The quantum second virial coefficient Bq of 3He↑ gas is determined in the temperature range 0.001-4 K from the Beth-Uhlenbeck formula. The corresponding phase shifts are calculated from the Lippmann-Schwinger equation using a highly-accurate matrix-inversion technique. A positive Bq corresponds to an overall repulsive interaction; whereas a negative Bq represents an overall attractive interaction. It is found that in the low-energy limit, Bq tends to increase with increasing spin polarization. The compressibility Z is evaluated as another measure of nonideality of the system. Z becomes most significant at low temperatures and increases with polarization. From the pressure-temperature (P-T) behavior of 3He↑ at low T, it is deduced that P decreases with increasing T below 8 mK.

  13. Towards a 20 kA high temperature superconductor current lead module using REBCO tapes

    Science.gov (United States)

    Heller, R.; Bagrets, N.; Fietz, W. H.; Gröner, F.; Kienzler, A.; Lange, C.; Wolf, M. J.

    2018-01-01

    Most of the large fusion devices presently under construction or in operation consisting of superconducting magnets like EAST, Wendelstein 7-X (W7-X), JT-60SA, and ITER, use high temperature superconductor (HTS) current leads (CL) to reduce the cryogenic load and operational cost. In all cases, the 1st generation HTS material Bi-2223 is used which is embedded in a low-conductivity matrix of AgAu. In the meantime, industry worldwide concentrates on the production of the 2nd generation HTS REBCO material because of the better field performance in particular at higher temperature. As the new material can only be produced in a multilayer thin-film structure rather than as a multi-filamentary tape, the technology developed for Bi-2223-based current leads cannot be transferred directly to REBCO. Therefore, several laboratories are presently investigating the design of high current HTS current leads made of REBCO. Karlsruhe Institute of Technology is developing a 20 kA HTS current lead using brass-stabilized REBCO tapes—as a further development to the Bi-2223 design used in the JT-60SA current leads. The same copper heat exchanger module as in the 20 kA JT-60SA current lead will be used for simplicity, which will allow a comparison of the newly developed REBCO CL with the earlier produced and investigated CL for JT-60SA. The present paper discusses the design and accompanying test of single tape and stack REBCO mock-ups. Finally, the fabrication of the HTS module using REBCO stacks is described.

  14. A test rig for analysis of adhesive tapes at 4 K cryogenic temperature

    Science.gov (United States)

    Funke, Thomas; Germer, Alexander; Haberstroh, Christoph; Mayrhofer, Robert; Stipsitz, Johannes

    2017-02-01

    Cryostats and dewar vessels, in particular those used for liquid helium applications, are usually equipped with multi-layer insulation (MLI). Thereby, multiple foils are wrapped around the respective vessels, tubing and components. As standard, different foils are bonded edge to edge using adhesive tapes either based on aluminized non-metallic films or on aluminum foil. There are a number of standard test procedures for adhesive tapes near ambient temperatures (e.g. AFERA 5012/ISO 29863) allowing a standardized characterization of tapes in terms of holding force and long-term reliability. Unfortunately this does not hold true for adhesive tapes to be used at cryogenic temperatures. In this respect, a test rig comprised of a spring-based traction mechanism has been developed by the authors. Combined with a liquid helium dewar, the fabricated test set-up allows a precise and reproducible application of an adjustable tensile load at 4.2 K and measurements of the respective holding time. In the following, the overall set-up including its significant features is described and first experimental results with aluminum tapes are presented.

  15. Potassium isotope fractionation between K-salts and saturated aqueous solutions at room temperature: Laboratory experiments and theoretical calculations

    Science.gov (United States)

    Li, Weiqiang; Kwon, Kideok D.; Li, Shilei; Beard, Brian L.

    2017-10-01

    Improvements in mass spectrometry have made it possible to identify naturally occurring K isotope (39K/41K) variability in terrestrial samples that can be used in a variety of geological and biological applications that involve cycling of K such as clay or evaporite formation. However, our ability to interpret K isotope variability is limited by a poor understanding of how K isotopes are fractionated at low temperatures. In this study, we conducted recrystallization experiments of eight K-salts in order to measure the K isotope fractionation factor between the salt and the saturated K solution (Δ41Kmin-sol). Measured Δ41Kmin-sol are +0.50‰ for K2CO3·1.5H2O, +0.32‰ for K2SO4, +0.23‰ for KHCO3, +0.06‰ for K2C2O4·H2O, +0.02‰ for KCl, -0.03‰ for K2CrO4, -0.15‰ for KBr, and -0.52‰ for KI. Overall the Δ41Kmin-sol decreases with increasing r for K in crystals, where r is the average distance between a K atom and its neighboring atoms of negative charge. Salts with monovalent anions and salts with divalent anion complexes define different linear trends with distinct slopes on a plot of Δ41Kmin-sol - r. We applied ab initio lattice dynamics and empirical crystal-chemistry models to calculation of K isotope fractionation factors between K salts; both methods showed that the calculated inter-mineral K isotope fractionation factors (Δ41Kmin-KCl) are highly consistent with experimentally derived Δ41Kmin-KCl under the assumption of consistent β factors for different saturated K solutions. Formulations for the crystal-chemistry model further indicate that both anion charge and bond length r are the principle controlling factors for K isotope fractionation, and the K isotope fractionation factors correlate with r following a 1/r3 relationship. Our experiment and theoretical study confirms the existence of significant equilibrium K isotope fractionation at ambient conditions, and the K isotope fractionation factors for halides and sulfate obtained in this

  16. Study of the system responsivity to measure the blackbody's temperature by optical pyrometry from 1200 K to 1570 K

    Directory of Open Access Journals (Sweden)

    Abbane Saif

    2017-01-01

    Full Text Available This work presents a method that has been recently adopted in our laboratory to determine the temperatures of blackbody sources in the range of 1200–1570 K. The system uses a Double Monochromator System (DMS based on a grating and a prism as dispersion elements. The detection element was a silicon photodiode (Si-MMA, over which the spectral range from 800 nm to 900 nm has been used. Between the blackbody source and the DMS was placed an optical system consists of two convergent lenses. The system responsivity “G” was determined by the transmission factor of the optical system and the transmission factor of the DMS and the photodiode responsivity. The obtained results showed that the relative uncertainty of the system responsivity “G” varied from 0.3% to 1.12%. This in turn resulted in a corresponding uncertainty in temperature of about 2.2 K and 4.5 K (k = 1 over the evaluated temperature range. Although this uncertainty level was significantly high compared to those obtained by many other national metrology institutes, it was considered as a step forward in our laboratory to measure high temperatures.

  17. Temperature dependent kinetics (195-798 K) and H atom yields (298-498 K) from reactions of (1)CH(2) with acetylene, ethene, and propene.

    Science.gov (United States)

    Gannon, K L; Blitz, M A; Liang, C H; Pilling, M J; Seakins, P W; Glowacki, D R

    2010-09-09

    The rate coefficients for the removal of the excited state of methylene, (1)CH(2) (a(1)A(1)), by acetylene, ethene, and propene have been studied over the temperature range 195-798 K by laser flash photolysis, with (1)CH(2) being monitored by laser-induced fluorescence. The rate coefficients of all three reactions exhibit a negative temperature dependence that can be parametrized as k((1)CH(2)+C(2)H(2)) = (3.06 +/- 0.11) x 10(-10) T ((-0.39+/-0.07)) cm(3) molecule(-1) s(-1), k((1)CH(2)+C(2)H(4)) = (2.10 +/- 0.18) x 10(-10) T ((-0.84+/-0.18)) cm(3) molecule(-1) s(-1), k((1)CH(2)+C(3)H(6)) = (3.21 +/- 0.02) x 10(-10) T ((-0.13+/-0.01)) cm(3) molecule(-1) s(-1), where the errors are statistical at the 2sigma level. Removal of (1)CH(2) occurs by chemical reaction and electronic relaxation to ground state triplet methylene. The H atom yields from the reactions of (1)CH(2) with acetylene, ethene, and propene have been determined by laser-induced fluorescence over the temperature range 298-498 K. For the reaction with propene, H atom yields are close to the detection limit, but for acetylene and ethene, the fraction of H atom production is approximately 0.88 and 0.71, respectively, at 298 K, rising to unity by 398 K, with the balance of the reaction with acetylene presumed to be electronic relaxation. Experimental constraints limit studies to a maximum of 1 Torr of bath gas; master equation calculations using an approach that allows treatment of intermediates with deep energy wells have been carried out to explore the role of collisional stabilization for the reaction of (1)CH(2) with acetylene. Stabilization is calculated to be insignificant under the experimental conditions, but does become significant at higher pressures. Between pressures of 100 and 1000 Torr, propyne and allene are formed in similar amounts with a slight preference for propyne. At higher pressures propyne formation becomes about a factor two greater than that of allene, and above 10(5) Torr (300 < T

  18. Iron Disilicide as High-Temperature Reference Material for Traceable Measurements of Seebeck Coefficient Between 300 K and 800 K

    Science.gov (United States)

    Ziolkowski, Pawel; Stiewe, Christian; de Boor, Johannes; Druschke, Ines; Zabrocki, Knud; Edler, Frank; Haupt, Sebastian; König, Jan; Mueller, Eckhard

    2017-01-01

    Thermoelectric generators (TEGs) convert heat to electrical energy by means of the Seebeck effect. The Seebeck coefficient is a central thermoelectric material property, measuring the magnitude of the thermovoltage generated in response to a temperature difference across a thermoelectric material. Precise determination of the Seebeck coefficient provides the basis for reliable performance assessment in materials development in the field of thermoelectrics. For several reasons, measurement uncertainties of up to 14% can often be observed in interlaboratory comparisons of temperature-dependent Seebeck coefficient or in error analyses on currently employed instruments. This is still too high for an industrial benchmark and insufficient for many scientific investigations and technological developments. The TESt (thermoelectric standardization) project was launched in 2011, funded by the German Federal Ministry of Education and Research (BMBF), to reduce measurement uncertainties, engineer traceable and precise thermoelectric measurement techniques for materials and TEGs, and develop reference materials (RMs) for temperature-dependent determination of the Seebeck coefficient. We report herein the successful development and qualification of cobalt-doped β-iron disilicide ( β-Fe0.95Co0.05Si2) as a RM for high-temperature thermoelectric metrology. A brief survey on technological processes for manufacturing and machining of samples is presented. Focus is placed on metrological qualification of the iron disilicide, results of an international round-robin test, and final certification as a reference material in accordance with ISO-Guide 35 and the "Guide to the expression of uncertainty in measurement" by the Physikalisch-Technische Bundesanstalt, the national metrology institute of Germany.

  19. Evaluation of the three-phase equilibrium method for measuring temperature dependence of internally consistent partition coefficients (K(OW), K(OA), and K(AW)) for volatile methylsiloxanes and trimethylsilanol.

    Science.gov (United States)

    Xu, Shihe; Kropscott, Bruce

    2014-12-01

    Partitioning equilibria and their temperature dependence of chemicals between different environmental media are important in determining the fate, transport, and distribution of contaminants. Unfortunately, internally consistent air/water (K(AW)), 1-octanol/air (K(OA)), and 1-octanol/water (K(OW)) partition coefficients, as well as information on their temperature dependence, are scarce for organosilicon compounds because of the reactivity of these compounds in water and octanol and their extreme partition coefficients. A newly published 3-phase equilibrium method was evaluated for simultaneous determination of the temperature dependence of (K(OW), K(OA), and K(AW)) of 5 volatile methylsiloxanes (VMS) and trimethylsilanol (TMS) in a temperature range from 4 °C to 35 °C. The measured partition coefficients at the different temperatures for any given compound, and the enthalpy and entropy changes for the corresponding partition processes, were all internally consistent, suggesting that the 3-phase equilibrium method is suitable for this type of measurement. Compared with common environmental contaminants reported in the literature, VMS have enthalpy and entropy relationships similar to those of alkanes for air/water partitioning and similar to those of polyfluorinated compounds for octanol/air partitioning, but more like those for benzoates and phenolic compounds for octanol/water partitioning. The temperature dependence of the partition coefficients of TMS is different from those of VMS and is more like that of alcohols, phenols, and sulfonamides. © 2014 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals, Inc.

  20. Transport current density at temperatures up to 25 K of Cu/Ag composite sheathed 122-type tapes and wires

    Science.gov (United States)

    Liu, Shifa; Lin, Kaili; Yao, Chao; Zhang, Xianping; Dong, Chiheng; Wang, Dongliang; Awaji, Satoshi; Kumakura, Hiroaki; Ma, Yanwei

    2017-11-01

    The fabrication of iron-based superconductors with high transport critical current density (J c) and low cost is a crucial determinant of whether they can be used for practical applications. In this paper, Cu/Ag composite sheathed Sr0.6K0.4Fe2As2 (Sr122) tapes and Ba0.6K0.4Fe2As2 (Ba122) round wires were fabricated via an ex situ powder-in-tube method and heat-treated by the hot pressing and hot isostatic pressing process respectively. In order to thoroughly reveal the application potential of Cu/Ag composite sheathed ‘122’ iron pnictide superconductors, transport J c of tapes and wires in high fields at temperatures up to 25 K was measured. High transport J c of 4.4 × 104 A cm-2 at 4.2 K and 3.6 × 103 A cm-2 at 20 K in 10 T was achieved in Cu/Ag composite sheathed Sr122 tapes. Transport J c of Ba122 wires is 9.4 × 103 A cm-2 at 4.2 K and 1.9 × 103 A cm-2 at 20 K in 10 T. These results demonstrate the great potential of Cu/Ag composite sheathed ‘122’ iron pnictide superconducting tapes and wires for high-field applications at intermediate temperatures around 20 K, which can be easily obtained by using cryocoolers.

  1. Densities and derived thermodynamic properties of 1-heptanol and 2-heptanol at temperatures from 313 K to 363 K and pressures up to 22 MPa

    Energy Technology Data Exchange (ETDEWEB)

    Zuniga-Moreno, Abel [Laboratorio de Termodinamica, ESIQIE, Instituto Politecnico Nacional, Edif. Z, Secc. 6, 1er piso, UPALM Zacatenco, 07738 Lindavista, Mexico, D.F. (Mexico); Galicia-Luna, Luis A. [Laboratorio de Termodinamica, ESIQIE, Instituto Politecnico Nacional, Edif. Z, Secc. 6, 1er piso, UPALM Zacatenco, 07738 Lindavista, Mexico, D.F. (Mexico)], E-mail: lgalicial@ipn.mx; Betancourt-Cardenas, Felix F. [Laboratorio de Termodinamica, ESIQIE, Instituto Politecnico Nacional, Edif. Z, Secc. 6, 1er piso, UPALM Zacatenco, 07738 Lindavista, Mexico, D.F. (Mexico)

    2008-01-15

    Experimental densities were determined in liquid phase for 1-heptanol and 2-heptanol at temperatures from 313 K to 363 K and pressures up to 22 MPa using a vibrating tube densimeter. Water and nitrogen were used as reference fluids for the calibration of the vibrating tube densimeter. The uncertainties of the experimental measurements in the whole range of reported data are estimated to be {+-}0.03 K for temperature, {+-}0.008 MPa for pressure, and {+-}0.20 kg . m{sup -3} for density. The experimental data are correlated using a short empirical equation of six parameters and the 11-parameter Benedict-Webb-Rubin-Starling equation of state (BWRS EoS) using a least square optimization. Statistical values to evaluate the different correlations are reported. Published density data of 1-heptanol are compared with values calculated with the 6-parameter equation using the parameters obtained in this work. The experimental data determined here are also compared with an available correlation for 1-heptanol. Densities of 2-heptanol at high pressure were not found in the literature and the data reported here represent the first set of data reported in the literature. Isothermal compressibilities and isobaric thermal expansivity are calculated using the 6-parameter equation for both alcohols within uncertainties estimated to be {+-}0.025 Gpa{sup -1} and {+-}4 x 10{sup -7} K{sup -1}, respectively.

  2. An ultra-low temperature scanning Hall probe microscope for magnetic imaging below 40 mK

    OpenAIRE

    Karci Ozgur; Piatek Julian O.; Jorba Pau; Dede Munir; Ronnow Henrik M.; Oral Ahmet

    2014-01-01

    We describe the design of a low temperature scanning Hall probe microscope (SHPM) for a dilution refrigerator system. A detachable SHPM head with 25.4 mm OD and 200 mm length is integrated at the end of the mixing chamber base plate of the dilution refrigerator insert (Oxford Instruments, Kelvinox MX-400) by means of a dedicated docking station. It is also possible to use this detachable SHPM head with a variable temperature insert (VTI) for 2 K-300 K operations. A microfabricated 1 mu m size...

  3. Noise measurement system at electron temperature down to 20 mK with combinations of the low pass filters.

    Science.gov (United States)

    Hashisaka, Masayuki; Yamauchi, Yoshiaki; Chida, Kensaku; Nakamura, Shuji; Kobayashi, Kensuke; Ono, Teruo

    2009-09-01

    We developed a quantum noise measurement system in a dilution refrigerator by using three kinds of cryogenic low pass filters. One of them is a commercial low pass filter inserted into the noise measurement lines instead of the conventional powder filter, which assures well-defined circuit parameters necessary for the noise measurement at a finite frequency. We checked that this filter gives sufficiently large attenuation up to 20 GHz at room temperature, 77 and 4.2 K. The electron temperature of the mesoscopic device placed in the present system was confirmed to be down to around 20 mK by measuring the thermal noise of the device.

  4. An ultra-low temperature scanning Hall probe microscope for magnetic imaging below 40 mK

    Science.gov (United States)

    Karcı, Özgür; Piatek, Julian O.; Jorba, Pau; Dede, Münir; Rønnow, Henrik M.; Oral, Ahmet

    2014-10-01

    We describe the design of a low temperature scanning Hall probe microscope (SHPM) for a dilution refrigerator system. A detachable SHPM head with 25.4 mm OD and 200 mm length is integrated at the end of the mixing chamber base plate of the dilution refrigerator insert (Oxford Instruments, Kelvinox MX-400) by means of a dedicated docking station. It is also possible to use this detachable SHPM head with a variable temperature insert (VTI) for 2 K-300 K operations. A microfabricated 1μm size Hall sensor (GaAs/AlGaAs) with integrated scanning tunneling microscopy tip was used for magnetic imaging. The field sensitivity of the Hall sensor was better than 1 mG/√Hz at 1 kHz bandwidth at 4 K. Both the domain structure and topography of LiHoF4, which is a transverse-field Ising model ferromagnet which orders below TC = 1.53 K, were imaged simultaneously below 40 mK.

  5. Compressed liquid densities of 1-butanol and 2-butanol at temperatures from 313 K to 363 K and pressures up to 25 MPa

    Energy Technology Data Exchange (ETDEWEB)

    Zuniga-Moreno, Abel [Laboratorio de Termodinamica, ESIQIE, Instituto Politecnico Nacional, Edif. Z, Secc. 6, 1ER Piso, UPALM, C.P. 07738, Mexico, D.F. (Mexico); Galicia-Luna, Luis A. [Laboratorio de Termodinamica, ESIQIE, Instituto Politecnico Nacional, Edif. Z, Secc. 6, 1ER Piso, UPALM, C.P. 07738, Mexico, D.F. (Mexico)]. E-mail: lgalicial@ipn.mx; Camacho-Camacho, Luis E. [Laboratorio de Termodinamica, ESIQIE, Instituto Politecnico Nacional, Edif. Z, Secc. 6, 1ER Piso, UPALM, C.P. 07738, Mexico, D.F. (Mexico)

    2007-02-15

    (p, {rho}, T) properties were determined in liquid phase for 1-butanol and 2-butanol at temperatures from 313 K to 363 K and pressures up to 25 MPa using a vibrating tube densimeter. The uncertainty is estimated to be lower than {+-}0.2 kg . m{sup -3} for the experimental densities. Nitrogen and water were used as reference fluids for the calibration of the vibrating tube densimeter. Experimental densities of 1-butanol and 2-butanol were correlated with a short empirical equation and the 11-parameter Benedict-Webb-Rubin-Starling equation of state (BWRS EoS) using a least square optimization. Statistical values to evaluate the different correlations were reported. Published densities of 1-butanol and 2-butanol are compared with values calculated with the BWRS EoS using the parameters obtained in this work. The experimental data determined here are also compared with available correlations for 1-butanol and 2-butanol.

  6. Spectrophotometric and Calorimetric Studies of Np(V) Complexation with Acetate at Variable Temperatures (T = 283 - 343 K)

    Energy Technology Data Exchange (ETDEWEB)

    Rao, Linfeng; Tian, Guoxin; Srinivasan, Thandankorai G.; Zanonato, PierLuigi; Di Bernardo, Plinio

    2009-12-21

    Spectrophotometric titrations were performed to identify the Np(V)/acetate complex and determine the equilibrium constants at variable temperatures (T = 283 - 343 K) and at the ionic strength of 1.05 mol {center_dot} kg{sup -1}. The enthalpy of complexation at corresponding temperatures was determined by microcalorimetric titrations. Results show that the complexation of Np(V) with acetate is weak but strengthened as the temperature is increased. The complexation is endothermic and is entropy-driven. The enhancement of the complexation at elevated temperatures is primarily due to the increasingly larger entropy gain when the solvent molecules are released from the highly-ordered solvation spheres of NpO{sub 2}{sup +} and acetate to the bulk solvent where the degree of disorder is higher at higher temperatures.

  7. GHRSST Level 4 K10_SST Global 1 meter Sea Surface Temperature Analysis (GDS version 1)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — A Group for High Resolution Sea Surface Temperature (GHRSST) Level 4 sea surface temperature analysis produced daily on an operational basis at the Naval...

  8. The interaction of O2 with the surface of polycrystalline gadolinium at the temperature range 300-670 K

    Science.gov (United States)

    Cohen, S.; Shamir, N.; Mintz, M. H.; Jacob, I.; Zalkind, S.

    2011-08-01

    Auger-Electron-Spectroscopy (AES) and Direct-Recoils-Spectrometry (DRS) were applied to study the interaction of O2 with a polycrystalline gadolinium surface, in the temperature range 300-670 K and oxygen pressure up to 2 × 10- 6 Torr. It has been found that initial uptake of oxygen, at coverage measurable by the techniques used here, results in rapid oxide island formation. The subsurface is believed to be a mixture of oxide particles and oxygen dissolved in the Gd metal, the latter being the mobile species, even at relatively low temperatures.Enhanced inward diffusion of oxygen starts as early as 420 K and dictates the surface oxygen concentration and effective thickness of the forming oxide. The oxygen accumulation rate at the near-surface region, as measured by the O(KLL) AES signal intensity, goes through a maximum as a function of temperature at 420 K. This is a result of the combination of still efficient oxygen chemisorption that increases surface occupation and slow inward diffusion. The thickest oxide, ~ 1.7 nm, is formed at 300 K and its effective thickness was found to decrease with increasing temperature (due to oxygen dissolution into the metal bulk).Diffusion coefficients of the oxygen dissolution into the bulk were evaluated for various temperatures utilizing models for infinitely thin oxide layer and thick oxide layer, respectively. The best fit under our experimental procedure was obtained by the thick layer model, and the coefficients that were calculated are D0 = 2.2 × 10- 16m2s- 1 and Ea = 46kJ/mol.

  9. Relative Distribution of Water Clusters at Temperature (300-3000K) and Pressure (1-500MPa)

    CERN Document Server

    Ri, Yong-U; Sin, Kye-Ryong

    2016-01-01

    At 300-3000K and 1-500MPa, variations of relative contents for small water clusters (H2O)n (n=1~6) were calculated by using statistical mechanical methods. First, 9 kinds of small water clusters were selected and their structures were optimized by using ab initio method. In the wide range of temperature (300-3000K) and pressure (1-500MPa), their equilibrium constants of reactions for formation of 9 kinds of water clusters were determined by using molecular partition function. Next, changes of contents (molar fractions) as function of temperature and pressure were estimated. The obtained results for small water clusters can be used to interpret temperature-pressure dependency of the average number for the hydrogen bonds in water clusters and redistribution of the water clusters at the ultrasonic cavitation reactions.

  10. Experiment K-7-35: Circadian Rhythms and Temperature Regulation During Spaceflight. Part 1; Circadian Rhythms and Temperature Regulation

    Science.gov (United States)

    Fuller, C. A.; Alpatov, A. M.; Hoban-Higgins, T. M.; Klimovitsky, V. Y.

    1994-01-01

    Mammals have developed the ability to adapt to most variations encountered in their everyday environment. For example, homeotherms have developed the ability to maintain the internal cellular environment at a relatively constant temperature. Also, in order to compensate for temporal variations in the terrestrial environment, the circadian timing system has evolved. However, throughout the evolution of life on earth, living organisms have been exposed to the influence of an unvarying level of earth's gravity. As a result changes in gravity produce adaptive responses which are not completely understood. In particular, spaceflight has pronounced effects on various physiological and behavioral systems. Such systems include body temperature regulation and circadian rhythms. This program has examined the influence of microgravity on temperature regulation and circadian timekeeping systems in Rhesus monkeys. Animals flown on the Soviet Biosatellite, COSMOS 2044, were exposed to 14 days of microgravity while constantly monitoring the circadian patterns temperature regulation, heart rate and activity. This experiment has extended our previous observations from COSMOS 1514, as well as providing insights into the physiological mechanisms that produce these changes.

  11. Measuring the microwave response of superconducting Nb:STO and Ti at mK temperatures using superconducting resonators

    Energy Technology Data Exchange (ETDEWEB)

    Thiemann, Markus; Beutel, Manfred; Dressel, Martin; Scheffler, Marc [1. Physikalisches Institut, Universitaet Stuttgart (Germany); Fillis-Tsirakis, Evangelos; Boschker, Hans; Mannhart, Jochen [Max Planck Institute for Solid State Research, Stuttgart (Germany)

    2016-07-01

    Niobium doped SrTiO{sub 3} is a superconductor, with the lowest charge carrier density among all superconductors. It shows a dome in the transition temperature as a function of doping concentration with a maximum T{sub c} ∼ 0.3 K. The superconducting dome may originate from the different bands being occupied depending on the doping level. The low energy scales of the system, as indicated by the low T{sub c} are within the GHz-regime. Therefore microwave measurements are a powerful technique to reveal the electronic properties of these superconductors. We preformed microwave measurements on Nb:STO of different doping levels in a dilution refrigerator, using superconducting stripline resonators. Measurements were done in a temperature and frequency range from 40-400 mK and 1-20 GHz, covering the normal and superconducting states. For comparison we also measured the temperature dependence of the surface impedance of superconducting titanium (T{sub c} ∼ 0.5 K), which can be well described by the Mattis-Bardeen equations with a ratio (2Δ)/(k{sub B}T{sub c}) = 3.56. Therefore titanium is an ideal reference sample representing a conventional BCS-superconductor.

  12. Challenges of Handling, Processing, and Studying Liquid and Supercooled Materials at Temperatures above 3000 K with Electrostatic Levitation

    Directory of Open Access Journals (Sweden)

    Takehiko Ishikawa

    2017-10-01

    Full Text Available Over the last 20 years, great progress has been made in techniques for electrostatic levitation, with innovations such as containerless thermophysical property measurements and combination of levitators with synchrotron radiation source and neutron beams, to name but a few. This review focuses on the technological developments necessary for handling materials whose melting temperatures are above 3000 K. Although the original electrostatic levitator designed by Rhim et al. allowed the handling, processing, and study of most metals with melting points below 2500 K, several issues appeared, in addition to the risk of contamination, when metals such as Os, Re, and W were processed. This paper describes the procedures and the innovations that made successful levitation and the study of refractory metals at extreme temperatures (>3000 K possible; namely, sample handling, electrode design (shape and material, levitation initiation, laser heating configuration, and UV range imaging. Typical results are also presented, putting emphasis on the measurements of density, surface tension, and viscosity of refractory materials in their liquid and supercooled phases. The data obtained are exemplified by tungsten, which has the highest melting temperature among metals (and is second only to carbon in the periodic table, rhenium and osmium. The remaining technical difficulties such as temperature measurement and evaporation are discussed.

  13. Raman spectroscopy of SrB4O7 single crystals in the temperature range 300-1273 K

    Science.gov (United States)

    Sobol, A. A.; Shukshin, V. E.; Zaitsev, A. I.

    2016-07-01

    The polarized Raman spectra of SrB4O7 (SBO) single crystals are studied in detail in the temperature range of 300-1273 K. The TO, LO, and IO phonon lines of A 1, A 2, B 1, and B 2 symmetries of rhombic SBO at 300 K are identified. The behavior of the Raman spectra of SBO crystals is studied upon heating up to their melting. The relation of Raman spectra with the structure of boron-oxygen fragments, as well as the transformation of spectra in the process of melting of SBO crystals, is discussed.

  14. Thermoelectric, electronic, optical and chemical bonding properties of Ba{sub 2}PrRuO{sub 6}: At temperature 7 K and 150 K

    Energy Technology Data Exchange (ETDEWEB)

    Reshak, A.H. [New Technologies-Research Center, University of West Bohemia, Univerzitni 8, 306 14 Pilsen (Czech Republic); Center of Excellence Geopolymer and Green Technology, School of Material Engineering, University Malaysia Perlis, Kangar, Perlis 01007 Malaysia (Malaysia); Khan, Wilayat, E-mail: walayat76@gmail.com [New Technologies-Research Center, University of West Bohemia, Univerzitni 8, 306 14 Pilsen (Czech Republic)

    2015-01-15

    Highlights: • DFT-FPLAPW method used for calculating the electronic structure. • The Fermi surface of BPRO (7 K and 150 K) is also calculated. • The complex dielectric function has been calculated. • Thermoelectric properties were also calculated using BoltzTraP code. • Power factor shows that both compounds are good thermoelectric materials at 600 K. - Abstract: We present first principles calculations of the band structure, density of states, electronic charge density, Fermi surface and optical properties of Ba{sub 2}PrRuO{sub 6} single crystals at two different temperatures. The atomic positions were optimized by minimizing the forces acting on the atoms. We have employed the full potential linear augmented plane wave method within local density approximation, generalized gradient approximation and Engel–Vosko generalized gradient approximation to treat the exchange correlation potential. The calculation shows that the compound is superconductor with strong hybridization near the Fermi energy level. Fermi surface is composed of two sheets. The calculated electronic specific heat capacities indicate, very close agreement with the experimental one. The bonding features of the compounds are analyzed using the electronic charge density in the (1 0 0) and (0–10) crystallographic planes. The dispersion of the optical constants was calculated and discussed. The thermoelectric properties are also calculated using the BoltzTrap code.

  15. PSI's 1kW imaging furnace-A tool for high-temperature chemical reactivity studies

    Energy Technology Data Exchange (ETDEWEB)

    Guesdon, C.; Alxneit, I.; Tschudi, H.R.; Wuillemin, D.; Brunner, Y.; Winkel, L.; Sturzenegger, M. [Laboratory for High-Temperature Solar Technology, Paul Scherrer Institut, 5232 Villigen PSI (Switzerland); Petrasch, J. [Professorship for Renewable Energy Carriers, ETHZ Zentrum, 8092 Zurich (Switzerland)

    2006-10-15

    A new experiment has been installed to conduct studies at temperatures as high as 2500K on chemical reactions that involve solids or melts and the release of condensable gases. The sample is radiatively heated by a 1kW xenon short arc lamp placed in the upper focus of a vertically oriented ellipsoid of revolution. The optimal optical configuration has been determined by a Monte-Carlo Ray tracing method. Several methods to machine the reflector have been evaluated by experimentally determining the optical quality of the surface of plane test pieces. In the imaging furnace the sample is placed on a water-cooled support and heated by the concentrated radiation. This arrangement allows for fast heating and impedes the reaction of the sample with crucible material. A remotely controlled hammer allows for freezing the high-temperature composition of the sample by a fast quench. Thus, the sample can be later analyzed by conventional methods such as XRD or TEM. To allow for measurements under defined atmospheres and to protect the ellipsoidal reflector from liberated condensable products, the entire sample stage is enclosed by a hemispherical glass dome. The dome itself is protected from condensable compounds by a laminar flow of inert gas. Experiments with an incense cone at the place of the sample to visualize the gas flow showed that a steady layer of inert gas protects the dome from smoke, if the inert gas flow is properly adjusted. Measured peak flux densities clearly exceed 500Wcm{sup -2} required to access temperatures of at least 2500K. Decomposition experiments on copper sulfides confirmed the operation of the furnace. In the near future flash assisted multi-wavelength pyrometry (FAMP) will be implemented to measure sample temperatures online. Though the imaging furnace was developed to study the decomposition of metal sulfides it is obviously suited to conduct high-temperature studies on most materials relevant for high-temperature solar technology. (author)

  16. Densities and volumetric properties of (acetonitrile+an amide) binary mixtures at temperatures between 293.15K and 318.15K

    Energy Technology Data Exchange (ETDEWEB)

    Nain, Anil Kumar [Department of Chemistry, Dyal Singh College, University of Delhi, New Delhi 110 003 (India)]. E-mail: ak_nain@yahoo.co.in

    2006-11-15

    The densities of binary mixtures of acetonitrile (ACN) with formamide (FA), N,N-dimethylformamide (DMF), N-methylacetamide (NMA), and N,N-dimethylacetamide (DMA), including those of pure liquids, over the entire composition range were measured at temperatures (293.15, 298.15, 303.15, 308.15, 313.15, and 318.15) K and atmospheric pressure. From the experimental data, the excess molar volume, V{sub m}{sup E}, and partial molar volumes, V-bar {sub m,1} and V-bar {sub m,2}, were calculated over whole composition range. The variation of these parameters with composition and temperature of the mixtures has been discussed in terms of molecular interaction in these mixtures. The V{sub m}{sup E} values were found negative for all the mixtures and at each temperature studied, indicating the presence of specific interactions between ACN and amide molecules. The extent of negative deviations in V{sub m}{sup E} values follows the order: FA>NMA>DMA>DMF. It is observed that the V{sub m}{sup E} values depend upon the positions of methyl groups in these amide molecules.

  17. Calculation of the second virial coefficient B(T) for gaseous and molecular hydrogen in the temperature range of 1 K to 3000 K. Berechnung des zweiten Virialkoeffizienten B(T) fuer gasfoermigen molekularen Wasserstoff im Temperaturintervall von 1 K bis 3000 K

    Energy Technology Data Exchange (ETDEWEB)

    Artym, R.; Kliem, M. (Energetisches Inst., Moscow (USSR))

    1991-10-01

    The second virial coefficient B(T) of hydrogen (H{sub 2}) has been calculated at temperatures over the range 1 K to 3000 K using the Woolley potential function. The potential constants {epsilon}/k = 28,79 K, r{sub m} = 0,34473 nm, e{sub 1} = 0,01 have been determined from the B(T)-data of Michels et al. (1959). The calculated second virial coefficients B(T) agree very well with the available experimental data over the whole temperature range from 13 K to 3000 K. A new method of calculating second virial coefficients has been suggested for low temperatures based on the representation of (y-y{sub 0})/(x-x{sub 0}) vs x by a straight line (x = T{sup 1/2}, y = T{sup 5/4} B). (orig.).

  18. Solubility of esomeprazole magnesium trihydrate in alcohols at temperatures from 298.15 to 318.15 K

    Science.gov (United States)

    Bhesaniya, K.; Baluja, S.

    2013-12-01

    The solubility of esomeprazole magnesium trihydrate in methanol, ethanol, 1-propanol and 1-butanol was determined at temperatures ranging from 298.15 to 318.15 K at atmospheric pressure using gravimetrical method. The highest solubility is found in 1-butanol and lowest in ethanol. The experimental solubility data are correlated by the modified Apelblat equation. Thermodynamic properties such as dissolution enthalpy, Gibb's energy, and entropy of mixing have been determined from the solubility data.

  19. cleaned glass substrates at room temperature (300°K). An ...

    Indian Academy of Sciences (India)

    The sheet resistivity of the as-deposited SnOz films was very high (> 20 M0) and decreased with annealing in air. The variation of sheet resistivity as a function of time during isothermal annealing at different temperatures is shown in figure 1. The as- deposited or unannealed SnO2 films (evaporatiOn temperature above ...

  20. Investigation of Electrical Latchup and SEL Mechanisms at Low Temperature for Applications Down to 50 K

    Science.gov (United States)

    Youssef, A. Al; Artola, L.; Ducret, S.; Hubert, G.; Perrier, F.

    2017-08-01

    This paper presents a physical investigation of the mechanisms induced by the low temperature on single-event latchup in CMOS inverters for a range of technology nodes (250 nm from Sofradir and 180 nm from IBM). For the first time, the TCAD simulations show a good agreement of latchup characteristics with the experimental measurements at cryogenic temperatures. Additionally, a more robust technology provided by Sofradir was demonstrated.

  1. Neutron experiments on nuclear order in silver at pK temperatures

    DEFF Research Database (Denmark)

    Nummila, K.K.; Tuoriniemi, J.T.; Vuorinen, R.T.

    1996-01-01

    Spontaneous long range antiferromagnetic order in the spin-1/2 s ystem of silver nuclei has been observed by neutron diffraction on a single crystal of Ag The observed antiferromagnetic state had a simple 1-k structure and no field induced phase transitions within the ordered state could be inden...

  2. Probing environment fluctuations by two-dimensional electronic spectroscopy of molecular systems at temperatures below 5 K

    Energy Technology Data Exchange (ETDEWEB)

    Rancova, Olga; Abramavicius, Darius [Department of Theoretical Physics, Vilnius University, Sauletekio al 9-III, 10222 Vilnius (Lithuania); Jankowiak, Ryszard [Department of Chemistry and Department of Physics, Kansas State University, 213 CBC Building Manhattan, Kansas 66506-0401 (United States)

    2015-06-07

    Two-dimensional (2D) electronic spectroscopy at cryogenic and room temperatures reveals excitation energy relaxation and transport, as well as vibrational dynamics, in molecular systems. These phenomena are related to the spectral densities of nuclear degrees of freedom, which are directly accessible by means of hole burning and fluorescence line narrowing approaches at low temperatures (few K). The 2D spectroscopy, in principle, should reveal more details about the fluctuating environment than the 1D approaches due to peak extension into extra dimension. By studying the spectral line shapes of a dimeric aggregate at low temperature, we demonstrate that 2D spectra have the potential to reveal the fluctuation spectral densities for different electronic states, the interstate correlation of static disorder and, finally, the time scales of spectral diffusion with high resolution.

  3. Practical thermometry and thermalization at sub-1 K temperatures using commercial surface-mount components

    Science.gov (United States)

    Beev, Nikolai; Kiviranta, Mikko

    2014-11-01

    Thermometry and heat sinking are important aspects of cryogenic engineering. We have carried out experiments to determine the usefulness of commercial surface-mount resistors, resistor arrays and capacitors as temperature sensors and electrically isolated heat conductors. Our investigations were motivated by the need for easy thermal diagnostics and management of heat dissipation in experimental setups operating at sub-kelvin temperatures in dilution refrigerators. In this work we also present a simple and robust resistance-to-voltage converter circuit with low excitation power.

  4. Thermal conductivity measurements of impregnated Nb3Sn coil samples in the temperature range of 3.5 K to 100 K

    Science.gov (United States)

    Koettig, T.; Maciocha, W.; Bermudez, S.; Rysti, J.; Tavares, S.; Cacherat, F.; Bremer, J.

    2017-02-01

    In the framework of the luminosity upgrade of the LHC, high-field magnets are under development. Magnetic flux densities of up to 13 T require the use of Nb3Sn superconducting coils. Quench protection becomes challenging due to the high stored energy density and the low stabilizer fraction. The thermal conductivity and diffusivity of the combination of insulating layers and Nb3Sn based cables are an important thermodynamic input parameter for quench protection systems and superfluid helium cooling studies. A two-stage cryocooler based test stand is used to measure the thermal conductance of the coil sample in two different heat flow directions with respect to the coil package geometry. Variable base temperatures of the experimental platform at the cryocooler allow for a steady-state heat flux method up to 100 K. The heat is applied at wedges style copper interfaces of the Rutherford cables. The respective temperature difference represents the absolute value of thermal conductance of the sample arrangement. We report about the measurement methodology applied to this kind of non-uniform sample composition and the evaluation of the used resin composite materials.

  5. Infrared normal spectral emissivity of Ti-6Al-4V alloy in the 500-1150 K temperature range

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez-Fernandez, L. [Departamento de Fisica de la Materia Condensada, Facultad de Ciencia y Tecnologia, Universidad del Pais Vasco, Barrio Sarriena s/n, 48940 Leioa, Bizkaia (Spain); Industria de Turbo Propulsores, S.A., Planta de Zamudio, Edificio 300, 48170 Zamudio, Bizkaia (Spain); Risueno, E. [CIC Energigune, Parque Tecnologico, Albert Einstein 48, 01510 Minano, Alava, Spain. (Spain); Perez-Saez, R.B., E-mail: raul.perez@ehu.es [Departamento de Fisica de la Materia Condensada, Facultad de Ciencia y Tecnologia, Universidad del Pais Vasco, Barrio Sarriena s/n, 48940 Leioa, Bizkaia (Spain); Instituto de Sintesis y Estudio de Materiales, Universidad del Pais Vasco, Apdo. 644,48080 Bilbao, Spain. (Spain); Tello, M.J. [Departamento de Fisica de la Materia Condensada, Facultad de Ciencia y Tecnologia, Universidad del Pais Vasco, Barrio Sarriena s/n, 48940 Leioa, Bizkaia (Spain); Instituto de Sintesis y Estudio de Materiales, Universidad del Pais Vasco, Apdo. 644,48080 Bilbao, Spain. (Spain)

    2012-11-15

    Highlights: Black-Right-Pointing-Pointer First heating cycle acts as a annealing, relieving the surface stresses. Black-Right-Pointing-Pointer Stress relieving occurs mainly above 900 K. Black-Right-Pointing-Pointer Emissivity decreases between 0.35 and 0.10 in the 2.5-22 {mu}m spectral range. Black-Right-Pointing-Pointer Emissivity increases linearly with temperature, with the same slope for {lambda} > 10 {mu}m. Black-Right-Pointing-Pointer Good agreement between resistivity and emissivity by means of Hagen-Rubens relation. - Abstract: Thermal radiative emissivity is related to the optical and electrical properties of materials, and it is a key parameter required in a large number of industrial applications. In the case of Ti-6Al-4V, spectral emissivity experimental data are not available for the range of temperatures between 400 and 1200 K, where almost all industrial applications take place. The experimental results in this paper show that the normal spectral emissivity decreases with wavelength from a value of about 0.35 at 2.5 {mu}m to about 0.10 at 22 {mu}m. At the same time, the spectral emissivity shows a slight linear increase with temperature between 500 and 1150 K, with approximately the same slope for all wavelengths. Additionally, the influence of the samples thermal history on the emissivity is studied. A strong decrease in the emissivity values appears due to the effect of surface stress relaxation processes. This means that the radiative properties of this alloy strongly depend on the surface stress state. A thermal treatment to relieve the surface stress should be carried out to achieve a steady state of the radiative properties. In addition, a good qualitative agreement is found between the temperature dependence of the electrical resistivity obtained using conventional measurements and the one obtained from the emissivity experimental results by using the Hagen-Rubens equation.

  6. Effect of the slow (K or rapid (k+ feathering gene on body and feather growth and fatness according to ambient temperature in a Leghorn × brown egg type cross

    Directory of Open Access Journals (Sweden)

    Bordas André

    2001-11-01

    Full Text Available Abstract Chicks of both sexes issued from the cross of heterozygous K/k+ cocks for the slow-feathering sex linked K allele with k+ (rapid feathering hens, were compared from the age of 4 to 10 weeks at two ambient temperatures. In individual cages, 30 male chicks of each genotype (K/k+ and k+/k+ were raised at 21°C, and 60 others, distributed in the same way, were raised at 31°C. 71 K/W females and 69 k+/W females were raised in a floor pen at 31°C till 10 weeks of age. In the males, the body weight, feed consumption and feed efficiency at different ages were influenced only by temperature (lower growth rate and feed intake at 31°C; no significant effects of the genotype at locus K nor genotype × temperature interaction were observed. In females, all at 31°C, the genotype (K/W or k+/W had no significant effect on growth rate. Plumage weight and weight of abdominal fat (absolute or related to body weight were measured on half of the males of each group in individual cages, at 10 weeks of age. Moreover, on 36 males and 48 females of the two genotypes, in a group battery at 31°C, the absolute and relative weight of plumage were measured on a sample every two weeks between 4 and 10 weeks. In the first case, no significant effect of genotype appeared. In the second case, an interaction between age and genotype was suggested from plumage weight: its growth, especially in male chicks, appears to be temporarily and unexpectedly faster from 4 to 6 weeks of age for the K/k+ and K/W genotypes.

  7. Optical Refrigeration to 119 K, below National Institute of Standards and Technology Cryogenic Temperature

    Science.gov (United States)

    2013-05-01

    New Mexico 87131, USA 2NEST, Nanoscience Insitute -CNR, Dipartimento di Fisica , Universita’ di Pisa, Largo B. Pontecorvo, Pisa 3-56127, Italy 3Air...Yb:fiber laser at 1020 nm from IPG Photonics. The experimental setup is outlined in Fig. 2. The laser is optically isolated from and focused via a lens...285 K. A cool- ing power of 50 mW was estimated at the steady state, which, within our experimental uncertainty, corresponds to the NIST-defined

  8. Optical properties of bismuth-doped silica fibres in the temperature range 300 - 1500 K

    Energy Technology Data Exchange (ETDEWEB)

    Dvoretskii, D A; Bufetov, Igor' A; Vel' miskin, V V; Zlenko, Alexander S; Khopin, V F; Semjonov, S L; Guryanov, Aleksei N; Denisov, L K; Dianov, Evgenii M

    2012-09-30

    The visible and near-IR absorption and luminescence bands of bismuth-doped silica and germanosilicate fibres have been measured for the first time as a function of temperature. The temperature-dependent IR luminescence lifetime of a bismuth-related active centre associated with silicon in the germanosilicate fibre has been determined. The Bi{sup 3+} profile across the silica fibre preform is shown to differ markedly from the distribution of IR-emitting bismuth centres associated with silicon. The present results strongly suggest that the IR-emitting bismuth centre comprises a lowvalence bismuth ion and an oxygen-deficient glass network defect. (optical fibres, lasers and amplifiers. properties and applications)

  9. Temperature Dependence of Spin Relaxation Time in InAs Columnar Quantum Dots at 10 to 150 K

    Science.gov (United States)

    Nakanishi, Sota; Sasayama, Kazutoshi; Oyanagi, Yoshitsugu; Yamaguchi, Ryo; Lu, Shulong; Li, Lianhe; Fiore, Andrea; Tackeuchi, Atsushi

    2012-04-01

    We have investigated carrier spin relaxation in InAs columnar quantum dots (CQDs) using time-resolved photoluminescence measurement. The CQDs were formed by depositing a 1.8 monolayer InAs seed dot layer and a short-period GaAs/InAs superlattice (SL). The spin relaxations of the 3- and 35-period SL CQDs show double exponential decay up to 50 and 130 K, respectively. The spin relaxation times of the fast component, whose amplitudes are 4-11 times larger than that of the slow component, are around 100 ps for the two samples. For the 3-period SL CQDs, the fast spin relaxation time shows no temperature dependence up to around 50 K, indicating the relevance of the Bir-Aronov-Pikus process. The slow spin relaxation time of the 35-period SL CQDs was found to decrease from 3.42 ns at 10 K to 0.849 ns at 130 K. This large change may be explained by the Elliott-Yafet process considering acoustic phonon scattering.

  10. A high-resolution combined scanning laser and widefield polarizing microscope for imaging at temperatures from 4 K to 300 K.

    Science.gov (United States)

    Lange, M; Guénon, S; Lever, F; Kleiner, R; Koelle, D

    2017-12-01

    Polarized light microscopy, as a contrast-enhancing technique for optically anisotropic materials, is a method well suited for the investigation of a wide variety of effects in solid-state physics, as, for example, birefringence in crystals or the magneto-optical Kerr effect (MOKE). We present a microscopy setup that combines a widefield microscope and a confocal scanning laser microscope with polarization-sensitive detectors. By using a high numerical aperture objective, a spatial resolution of about 240 nm at a wavelength of 405 nm is achieved. The sample is mounted on a 4He continuous flow cryostat providing a temperature range between 4 K and 300 K, and electromagnets are used to apply magnetic fields of up to 800 mT with variable in-plane orientation and 20 mT with out-of-plane orientation. Typical applications of the polarizing microscope are the imaging of the in-plane and out-of-plane magnetization via the longitudinal and polar MOKE, imaging of magnetic flux structures in superconductors covered with a magneto-optical indicator film via the Faraday effect, or imaging of structural features, such as twin-walls in tetragonal SrTiO3. The scanning laser microscope furthermore offers the possibility to gain local information on electric transport properties of a sample by detecting the beam-induced voltage change across a current-biased sample. This combination of magnetic, structural, and electric imaging capabilities makes the microscope a viable tool for research in the fields of oxide electronics, spintronics, magnetism, and superconductivity.

  11. A high-resolution combined scanning laser and widefield polarizing microscope for imaging at temperatures from 4 K to 300 K

    Science.gov (United States)

    Lange, M.; Guénon, S.; Lever, F.; Kleiner, R.; Koelle, D.

    2017-12-01

    Polarized light microscopy, as a contrast-enhancing technique for optically anisotropic materials, is a method well suited for the investigation of a wide variety of effects in solid-state physics, as, for example, birefringence in crystals or the magneto-optical Kerr effect (MOKE). We present a microscopy setup that combines a widefield microscope and a confocal scanning laser microscope with polarization-sensitive detectors. By using a high numerical aperture objective, a spatial resolution of about 240 nm at a wavelength of 405 nm is achieved. The sample is mounted on a 4He continuous flow cryostat providing a temperature range between 4 K and 300 K, and electromagnets are used to apply magnetic fields of up to 800 mT with variable in-plane orientation and 20 mT with out-of-plane orientation. Typical applications of the polarizing microscope are the imaging of the in-plane and out-of-plane magnetization via the longitudinal and polar MOKE, imaging of magnetic flux structures in superconductors covered with a magneto-optical indicator film via the Faraday effect, or imaging of structural features, such as twin-walls in tetragonal SrTiO3. The scanning laser microscope furthermore offers the possibility to gain local information on electric transport properties of a sample by detecting the beam-induced voltage change across a current-biased sample. This combination of magnetic, structural, and electric imaging capabilities makes the microscope a viable tool for research in the fields of oxide electronics, spintronics, magnetism, and superconductivity.

  12. System model development for a methanol reformed 5 kW high temperature PEM fuel cell system

    DEFF Research Database (Denmark)

    Sahlin, Simon Lennart; Andreasen, Søren Juhl; Kær, Søren Knudsen

    2015-01-01

    This work investigates the system performance when reforming methanol in an oil heated reformer system for a 5 kW fuel cell system. A dynamic model of the system is created and evaluated. The system is divided into 4 separate components. These components are the fuel cell, reformer, burner...... and evaporator, which are connected by two separate oil circuits, one with a burner and reformer and one with a fuel cell and evaporator. Experiments were made on the reformer and measured oil and bed temperatures are presented in multiple working points. The system is examined at loads from 0 to 5000 W electric...

  13. (Vapour + liquid) equilibrium in (N,N-dimethylacetamide + ethanol + water) at the temperature 313.15 K

    Energy Technology Data Exchange (ETDEWEB)

    Zielkiewicz, Jan [Department of Chemistry, Gdansk University of Technology, Narutowicza Str. 11/12, 80-952 Gdansk (Poland)]. E-mail: jaz@altis.chem.pg.gda.pl

    2006-06-15

    Total vapour pressures, measured at the temperature 313.15 K, are reported for the ternary mixture (N,N-dimethylacetamide + ethanol + water), and for binary constituent (N,N-dimethylacetamide + ethanol). The present results are also compared with previously obtained data for (amide + ethanol) binary mixtures, where amide = N-methylformamide, N,N-dimethylformamide, N-methylacetamide, 2-pyrrolidinone, and N-methylpyrrolidinone. We found that excess Gibbs free energy of mixing for binary (amide + ethanol) mixtures varies roughly linearly with the molar volume of amide.

  14. Thermodynamic Properties of Low-Density {}^{132}Xe Gas in the Temperature Range 165-275 K

    Science.gov (United States)

    Akour, Abdulrahman

    2018-01-01

    The method of static fluctuation approximation was used to calculate selected thermodynamic properties (internal energy, entropy, energy capacity, and pressure) for xenon in a particularly low-temperature range (165-270 K) under different conditions. This integrated microscopic study started from an initial basic assumption as the main input. The basic assumption in this method was to replace the local field operator with its mean value, then numerically solve a closed set of nonlinear equations using an iterative method, considering the Hartree-Fock B2-type dispersion potential as the most appropriate potential for xenon. The results are in very good agreement with those of an ideal gas.

  15. Apparent molar volumes and apparent molar heat capacities of aqueous N-acetyl-D-glucosamine at temperatures from 278.15 K to 368.15 K and of aqueous N-methylacetamide at temperatures from 278.15 K to 393.15 K at the pressure 0.35 MPa

    Energy Technology Data Exchange (ETDEWEB)

    Swenson, D.M. [Department of Chemistry and Biochemistry, Brigham Young University, Provo, UT 84602-5700 (United States); Ziemer, S.P. [Department of Chemistry and Biochemistry, Brigham Young University, Provo, UT 84602-5700 (United States); Blodgett, M.B. [Department of Chemistry and Biochemistry, Brigham Young University, Provo, UT 84602-5700 (United States); Jones, J.S. [Department of Chemistry and Biochemistry, Brigham Young University, Provo, UT 84602-5700 (United States); Woolley, E.M. [Department of Chemistry and Biochemistry, Brigham Young University, Provo, UT 84602-5700 (United States)]. E-mail: earl_woolley@byu.edu

    2006-12-15

    We determined apparent molar volumes V {sub {phi}} from densities measured with a vibrating-tube densimeter at 278.15 {<=} (T/K) {<=} 368.15 and apparent molar heat capacities C {sub p,{phi}} with a twin fixed-cell, differential, temperature-scanning calorimeter at 278.15 {<=} (T/K) {<=} 363.15 for aqueous solutions of N-acetyl-D-glucosamine at m from (0.01 to 1.0) mol . kg{sup -1} and at p = 0.35 MPa. We also determined V {sub {phi}} at 278.15 {<=} (T/K) {<=} 368.15 and C {sub p,{phi}} at 278.15 {<=} (T/K) {<=} 393.15 for aqueous solutions of N-methylacetamide at m from (0.015 to 1.0) mol . kg{sup -1} and at p = 0.35 MPa. Empirical functions of m and T for each compound were fitted to our results, which are then compared to those for N,N-dimethylacetamide. Estimated values of {delta}{sub r} V {sub m}(m, T) and {delta}{sub r} C {sub p,m}(m, T) for formation of aqueous N-acetyl-D-glucosamine from aqueous D-glucose and aqueous acetamide are calculated and discussed.

  16. Temperature Measurements Using Type K Thermocouples and the Fluke Helios Plus 2287A Datalogger

    DEFF Research Database (Denmark)

    Artmann, Nikolai; Vonbank, R.; Jensen, Rasmus Lund

    In 1821, the German–Estonian physicist Thomas Johann Seebeck discovered that when any conductor (such as a metal) is subjected to a thermal gradient, it will generate a voltage. This is now known as the thermoelectric effect or Seebeck effect. Any attempt to measure this voltage necessarily...... involves connecting another conductor to the "hot" end. This additional conductor will then also experience the temperature gradient, and develop a voltage of its own which will oppose the original. Fortunately, the magnitude of the effect depends on the metal in use. Using a dissimilar metal to complete...

  17. Effects of Novel Fin Shape of High Temperature Heat Exchanger on 1 kW Class Stirling Engine

    Energy Technology Data Exchange (ETDEWEB)

    Ahn, Joon; Kim, Seok Yeon [Kookmin Univ., Seoul (Korea, Republic of)

    2017-08-15

    In this research, numerical analysis was carried out on novel and existing fins, adjusted in terms of factors such as length, spacing, and angle, of a high-temperature heat exchanger for a 1 kW class Stirling engine, designed as a prime mover for a domestic cogeneration system. The performance improvement as a result of shape optimization was confirmed with numerical analysis by including the air preheater, which was not considered during optimization. However, a negative heat flux was observed in the cylinder head portion. This phenomenon was clarified by analyzing the exhaust gas and wall surface temperature of the combustion chamber. Furthermore, assuming an ideal cycle, the effects of heat transfer enhancement on the thermodynamic cycle and system performance were predicted.

  18. Operation experiences with a 30 kV/100 MVA high temperature superconducting cable system

    DEFF Research Database (Denmark)

    Tønnesen, Ole; Däumling, Manfred; Jensen, Kim Høj

    2004-01-01

    of this demonstration project is to gain experience with HTS cables under realistic conditions in a live distribution network. Approximately 50 000 utility customers have their electric power supplied through the HTS cable. The cable system has delivered 226 GW h of energy and reached a maximum operating current......A superconducting cable based on Bi-2223 tape technology has been developed, installed and operated in the public network of Copenhagen Energy in a two-year period between May 2001 and May 2003. This paper gives a brief overview of the system and analyses some of the operation experiences. The aim...... of 1157 A. The operation experiences include over-currents of 6 kA due to faults on peripheral lines, commissioning, servicing and failure responses on the cooling system, continuous 24 h, 7 day per week monitoring and performance of the alarm system. The implications of these experiences for the future...

  19. Bimetallic strip for low temperature use. [4-300/sup 0/K

    Science.gov (United States)

    Bussiee, J.F.; Welch, D.O.; Suenaga, M.

    A class of mechanically pre-stressed structures is provided suitably bi-layer strips, consisting of a layer of group 5 transition metals in intimate contact with a layer of an intermetallic compound of transition metals with certain group 3A, 4A or 5A metals or metalloids such as Ga, In, Si, Ge, Sn, As or Sb. The changes of Young's modulus of these bi-layered combinations at temperatures in the region of somewhat above absolute zero provides a useful means of sensing temperature changes. Such bi-metallic strips may be used as control strips in thermostats, or in direct dial reading instruments. The structures are made by preparing a sandwich of a group 5B transition metal strip between the substantially thicker strips of an alloy between copper and a predetermined group 3A, 4A or 5A metal or metalloid, holding the three layers are heated, cooled the copper alloys and is removed. Removing one of the two formed interlayer alloys between the transition metal and the metal previously alloyed with copper remain.

  20. MRI temperature map reconstruction directly from k-space with compensation for heating-induced geometric distortions

    Science.gov (United States)

    Gaur, Pooja; Grissom, William A.

    2017-03-01

    Proton resonance frequency (PRF) change is used to measure tissue heating, but also distorts the image and causes geometric distortions in temperature estimates in the same manner as other chemical shift distortions if left uncompensated. We propose an algorithm that produces PRF temperature maps free of these distortions by fitting a signal model directly to acquired k-space data that accounts for PRF-induced phase both up to and during the readout. We also introduce a faster method compatible with Cartesian data that corrects distortions from image-domain temperature maps. Gel heating experiments show the proposed CS compensation algorithms correct magnitude image artifacts and hotspot distortions. Without CS compensation, thermal dose values are overestimated in spiral data, and are spatially offset in 2DFT and EPI data. Compensating for heat-induced CS distortions improves the accuracy of temperature change and thermal dose measurements, and can have a significant positive impact on clinical and research applications of PRF-shift thermometry.

  1. Measurement and Analysis of Normal Zone Propagation in a ReBCO Coated Conductor at Temperatures Below 50K

    CERN Document Server

    van Nugteren, J; Wessel, S; Krooshoop, E; Nijhuis, A; ten Kate, H

    2015-01-01

    Measurements of the quasi-adiabatic normal zone propagation velocity and quench energies of a Superpower SCS4050 copper stabilised ReBCO superconducting tape are presented over a temperature range of 23 − 47 K; in parallel applied magnetic fields of 6, 10 and 14 T; and over a current range from 50% to 100% of Ic. The data are compared to results of analytic predictions and to one-dimensional numerical simulations. The availability of long lengths of ReBCO coated conductor makes the material interesting for many HTS applications operating well below the boiling point of liquid nitrogen, such as magnets and motors. One of the main issues in the design of such devices is quench detection and protection. At higher temperatures, the quench velocities in these materials are known to be about two orders of magnitude lower compared to low temperature superconductors, resulting in significantly smaller normal zones and the risk of higher peak temperatures. To investigate whether the same also holds for lower tempera...

  2. Photophysics of α-furil at room temperature and 77 K: Spectroscopic and quantum chemical studies

    Science.gov (United States)

    Kundu, Pronab; Chattopadhyay, Nitin

    2016-06-01

    Steady state and time resolved spectroscopic measurements have been exploited to assign the emissions from different conformations of α-furil (2, 2'-furil) in solution phase at room temperature as well as cryogen (liquid nitrogen, LN2) frozen matrices of ethanol and methylcyclohexane. Room temperature studies reveal a single fluorescence from the trans-planar conformer of the fluorophore or two fluorescence bands coming from the trans-planar and the relaxed skew forms depending on excitation at the nπ∗ or the ππ∗ absorption band, respectively. Together with the fluorescence bands, the LN2 studies in both the solvents unambiguously ascertain two phosphorescence emissions with lifetimes 5 ± 0.3 ms (trans-planar triplet) and 81 ± 3 ms (relaxed skew triplet). Quantum chemical calculations have been performed using density functional theory at CAM-B3LYP/6-311++G∗∗ level to prop up the spectroscopic surveillance. The simulated potential energy curves (PECs) illustrate that α-furil is capable of giving two emissions from each of the S1 and the T1 states - one corresponding to the trans-planar and the other to the relaxed skew conformation. Contrary to the other 1,2-dicarbonyl molecular systems like benzil and α-naphthil, α-furil does not exhibit any fluorescence from its second excited singlet (S2) state. This is ascribed to the proximity of the minimum of the PEC of the S2 state and the hill-top of the PEC of the S1 state.

  3. Effects of vacuum-ultraviolet irradiation on copper penetration into low-k dielectrics under bias-temperature stress

    Energy Technology Data Exchange (ETDEWEB)

    Guo, X.; Zheng, H.; Xue, P.; Shohet, J. L. [Plasma Processing and Technology Laboratory and Department of Electrical and Computer Engineering, University of Wisconsin-Madison, Madison, Wisconsin 53706 (United States); King, S. W. [Logic Technology Development, Intel Corporation, Hillsboro, Oregon 97124 (United States); Nishi, Y. [Department of Electrical Engineering, Stanford University, Stanford, California 94305 (United States)

    2015-01-05

    The effects of vacuum-ultraviolet (VUV) irradiation on copper penetration into non-porous low-k dielectrics under bias-temperature stress (BTS) were investigated. By employing x-ray photoelectron spectroscopy depth-profile measurements on both as-deposited and VUV-irradiated SiCOH/Cu stacks, it was found that under the same BTS conditions, the diffusion depth of Cu into the VUV-irradiated SiCOH is higher than that of as-deposited SiCOH. On the other hand, under the same temperature-annealing stress (TS) without electric bias, the Cu distribution profiles in the VUV-irradiated SiCOH were same with that for the as-deposited SiCOH. The experiments suggest that in as-deposited SiCOH, the diffused Cu exists primarily in the atomic state, while in VUV-irradiated SiCOH, the diffused Cu is oxidized by the hydroxyl ions (OH{sup −}) generated from VUV irradiation and exists in the ionic state. The mechanisms for metal diffusion and ion injection in VUV irradiated low-k dielectrics are discussed.

  4. Current oscillations in ultra-small superconducting Nb-Nb junctions formed by STM at mK temperatures

    Science.gov (United States)

    Dreyer, Michael; Roychowdhury, Anita; Dana, Rami

    2014-03-01

    Using etched Nb STM tips we formed ultra-small tunnel junctions on a Nb crystal at an effective temperature of ~ 200 mK using an Oxford dilution refrigerator. The Nb crystal was prepared in UHV and then transferred into the mK STM. The resulting superconductor-insulator-superconductor (SIS) junction displayed several sub-gap features from multiple Andreev reflections to a zero bias conductance peak. The latter showed features of a Josephson junction in the phase diffusion limit with side structures due to the electrical environment. Upon microwave irradiation the peak split into multiple peaks in accordance with theory, verifying Josephson tunneling. In addition we observed bias dependent oscillations of the tunneling current. The oscillations where recorded at a rate of 10 kS/s while acquiring conventional dI/dV or I(V) spectroscopic curves. Histograms of the current for each bias voltage step then reveal the nature of the oscillation. It ranges from multiple states in certain bias regions through pure oscillations to supercurrent-normal switching. Fourier transform of the current show in some cases a bias dependence of the main frequencies. Possible causes will be discussed.

  5. Fluoride salts as phase change materials for thermal energy storage in the temperature range 1000-1400 K

    Science.gov (United States)

    Misra, Ajay K.

    1988-01-01

    Eutectic compositions and congruently melting intermediate compounds in binary and ternary fluoride salt systems were characterized for potential use as latent heat of fusion phase change materials to store thermal energy in the temperature range 1000-1400 K. The melting points and eutectic compositions for many systems with published phase diagrams were experimentally verified and new eutectic compositions having melting points between 1000 and 1400 K were identified. Heats of fusion of several binary and ternary eutectics and congruently melting compounds were experimentally measured by differential scanning calorimetry. For a few systems in which heats of mixing in the melts have been measured, heats of fusion of the eutectics were calculated from thermodynamic considerations and good agreement was obtained between the measured and calculated values. Several combinations of salts with high heats of fusion per unit mass (greater than 0.7 kJ/g) have been identified for possible use as phase change materials in advanced solar dynamic space power applications.

  6. Forced convection of ammonia. 2. part.: gaseous ammonia - very high wall temperatures (1000 to 3000 K); Convection forcee de l'ammoniac. 2. partie: ammoniac gazeux - cas de tres hautes temperatures de paroi (1000 a 3000{sup 0} K)

    Energy Technology Data Exchange (ETDEWEB)

    Perroud, P.; Rebiere, J.; Strittmatter, R. [Commissariat a l' Energie Atomique, Grenoble (France). Centre d' Etudes Nucleaires

    1969-07-01

    Heat transfer coefficients and pressure drop of gaseous ammonia in forced convection are experimentally determined. The fluid flows (mass flow rate 0.6 to 2.4 g/s) in a long tungsten tube (d{sub i} = 2.8 mm, d{sub e} = 5.1 mm, L = 700 mm) electrically heated. The temperature of the wall reaches 3000 deg. K and the fluid 2500 deg. K; maximum heat flux 530 w/cm{sup 2}. Ammonia is completely dissociated and the power necessary for dissociation reaches 30 per cent of the total power exchanged. Inlet pressure varies between 6 and 16 bars and the maximum pressure drop in the tube reaches 15 bars. Two regimes of dissociation have been shown: catalytic and homogeneous and the variation of dissociation along the length of the tube is studied. The measured heat transfer coefficients may be about 10 times these calculated by the means of classical formulae. A correlation of experimental results using enthalpy as a driving force for heat transmission is presented. Pressure drops may be calculated by the means of a classical friction factor. (authors) [French] On determine experimentalement les coefficients d'echange thermique et les pertes de charge de l'ammoniac gazeux en convection forcee. Le fluide circule avec un debit en masse compris entre 0.6 et 2.4 g/s (G = 10 a 40 g/cm{sup 2}.s) dans un tube long en tungstene (d{sub i} = 2.8 mm, d{sub e} = 5.1 mm, L = 700 mm), chauffe electriquement. La temperature de paroi atteint 3000 deg. K, celle du fluide 2500 deg. K et le flux de chaleur maximal est de 530 W/cm{sup 2}. L'ammoniac se dissocie completement, la puissance correspondant a la dissociation atteint 30 pour cent de la puissance totale echangee. La pression d'entree varie entre 6 et 16 bars et la chute de pression maximale dans le canal est de 15 bars. On distingue deux regimes de dissociation, catalytique et homogene, et on etudie la variation du taux de dissociation en fonction de la longueur du tube. Les coefficients d'echange thermique mesures

  7. Resistance of LHC main bus bar splices at room temperature and at 77.4 K

    CERN Document Server

    Heck, S; Scheuerlein, Chr; CERN. Geneva. TE Department

    2009-01-01

    As part of the quality control the resistance of newly produced LHC main bus bar splices is now routinely measured at room temperature (RT) in order to conclude on the electrical continuity of the bus bar stabiliser across the splice under operating conditions. In this note we present splice resistance measurements that have been performed at RT and in liquid nitrogen (LN) in the CERN Cryolab with “ideal” splices (represented by continuous dipole and quadrupole bus bars), and with dipole and quadrupole splices with different defects, which cause an additional RT splice resistance of up to 60 µΩ. The RT resistance (RRT) results obtained with the Cryolab set-up are compared to the calculated resistance values and with the so-called R-8 and R-16 resistance results, as they are measured in the LHC tunnel with a Digital Low Resistance Ohmmeter with a voltage tap distance of 8 cm or 16 cm. The RT to LN resistance ratio has been determined for all splices in order to study the influence of the resistance of th...

  8. Oxygen nonstoichiometry and thermodynamic characterization of Zr doped ceria in the 1573-1773 K temperature range.

    Science.gov (United States)

    Takacs, M; Scheffe, J R; Steinfeld, A

    2015-03-28

    This work encompasses the thermodynamic characterization and critical evaluation of Zr(4+) doped ceria, a promising redox material for the two-step solar thermochemical splitting of H2O and CO2 to H2 and CO. As a case study, we experimentally examine 5 mol% Zr(4+) doped ceria and present oxygen nonstoichiometry measurements at elevated temperatures ranging from 1573 K to 1773 K and oxygen partial pressures ranging from 4.50 × 10(-3) atm to 2.3 × 10(-4) atm, yielding higher reduction extents compared to those of pure ceria under all conditions investigated, especially at the lower temperature range and at higher pO2. In contrast to pure ceria, a simple ideal solution model accounting for the formation of isolated oxygen vacancies and localized electrons accurately describes the defect chemistry. Thermodynamic properties are determined, namely: partial molar enthalpy, entropy, and Gibbs free energy. In general, partial molar enthalpy and entropy values of Zr(4+) doped ceria are lower. The equilibrium hydrogen yields are subsequently extracted as a function of the redox conditions for dopant concentrations as high as 20%. Although reduction extents increase greatly with dopant concentration, the oxidation of Zr(4+) doped ceria is thermodynamically less favorable compared to pure ceria. This leads to substantially larger temperature swings between reduction and oxidation steps, ultimately resulting in lower theoretical solar energy conversion efficiencies compared to ceria under most conditions. In effect, these results point to the importance of considering oxidation thermodynamics in addition to reduction when screening potential redox materials.

  9. Measurement of the Absorptance-emittance of Black Paint Surfaces at Temperatures From 10 To 120[K].

    Science.gov (United States)

    Jamotton, P.; Delree, C.; Cucchiaro, A.; Liebecq, S.

    2004-08-01

    The PLANCK satellite, the third medium-size (M3) mission of Horizon 2000 program of the European Space Agency, will provide data to understand the origin and the evolution of our Universe. CSL is in charge of the whole satellite thermal vacuum testing, and will perform the only on-ground verification of the overall satellite, including its thermal performances. It is necessary to reproduce the deep cold space by thermal shrouds. The thermal requirements for these shrouds are not only to support a heat load of 50 [W] at a temperature lower than 20 [K] but also mainly to avoid cross-coupling from the warm parts of the spacecraft to the colder payload. The thermal shrouds are copper plates coated with a black paint on their inner face. Due to the main requirement, the choice of the paint, driven by its emittance-absorptance property, is one of the major parameter of the test set-up. A measurement bench for emittance-absorptance measurements was developed previously[1] for the testing of the METEOSAT SECOND GENERATION (MSG) set-up at CSL premises. The measurements were performed on flat plates and on an aluminium open honeycomb glued on a copper plate. The results showed that the best coating for this type of application is the PU1 paint from MAP in France. Due to the criticality of this parameter, deeper investigations on flat and open honeycomb surfaces absorptance-emittance measurements were required. The measurement bench has been improved, and the measurement post-treatment has also been strongly modified. Measurements of absorptance at 10 [K], for radiation coming from body in the range from 40 to 120 [K], have been performed together with emittance measurements in the range from 40 to 80 [K].

  10. Growth temperature regulation of some genes that define the superficial capsular carbohydrate composition of Escherichia coli K92.

    Science.gov (United States)

    Navasa, Nicolás; Rodríguez-Aparicio, Leandro B; Ferrero, Miguel Ángel; Moteagudo-Mera, Andrea; Martínez-Blanco, Honorina

    2011-07-01

    We studied growth temperature as a factor controlling the expression of genes involved in capsular polymers of Escherichia coli K92. These genes are shown to be regulated by growth temperature. Expression levels of genes belonging to the kps cluster, responsible for polysialic acid (PA) biosynthesis, were significantly increased at 37 °C compared with at 19 °C, being up to 500-fold increased for neuE and neuS genes. Similarly, the genes for the nan operon, responsible for PA catabolism, also reached higher expression levels at 37 °C, although with slightly lower values (39-141-fold). In contrast, genes of the cps operon, which are implicated in colanic acid (CA) metabolism, were upregulated when the bacteria were grown at 19 °C, albeit to a much lesser extent (around twofold). This different regulation of genes involved in the biosynthesis of polysialic and CAs correlates with the reported maximal production temperatures for the two polymers. The results suggest that the metabolism of PA is predominantly regulated by changes in gene expression, while CA production may be regulated mainly by post-transcriptional processes such as phosphorylation-dephosphorylation reactions. © 2011 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd. All rights reserved.

  11. Medium decoupling of dynamics at temperatures ~100 K above glass-transition temperature: a case study with (acetamide + lithium bromide/nitrate) melts.

    Science.gov (United States)

    Guchhait, Biswajit; Daschakraborty, Snehasis; Biswas, Ranjit

    2012-05-07

    Time-resolved fluorescence Stokes shift and anisotropy measurements using a solvation probe in [0.78CH(3)CONH(2) + 0.22{f LiBr + (1-f) LiNO(3)}] melts reveal a strong decoupling of medium dynamics from viscosity. Interestingly, this decoupling has been found to occur at temperatures ∼50-100 K above the glass transition temperatures of the above melt at various anion concentrations (f(LiBr)). The decoupling is reflected via the following fractional viscosity dependence (η) of the measured average solvation and rotation times ( and , respectively): ∝ (η∕T)(p) (x being solvation or rotation), with p covering the range, 0.20 than for , indicating a sort of translation-rotation decoupling. Multiple probes have been used in steady state fluorescence measurements to explore the extent of static heterogeneity. Estimated experimental dynamic Stokes shift for coumarin 153 in these mixtures lies in the range, 1000 < Δν(t)/cm(-1) < 1700, and is in semi-quantitative agreement with predictions from our semi-molecular theory. The participation of the fluctuating density modes at various length-scales to the observed solvation times has also been investigated.

  12. The Conductivity of Aqueous K2CO3 at Elevated Temperatures and Pressures, Measured using the AC van der Pauw Technique

    DEFF Research Database (Denmark)

    Mollerup, Pia Lolk; Christiansen, Ane Sælland; Bonanos, Nikolaos

    2013-01-01

    Conductivity measurements of aqueous K2CO3 were performed using the van der Pauw method and a specially designed sample holder with Pt wires as electrodes. The resistance was measured using alternating current. The conductivity of 10-50 wt% aqueous K2CO3 was measured at room temperature and ambie...

  13. Medium decoupling of dynamics at temperatures ˜100 K above glass-transition temperature: A case study with (acetamide + lithium bromide/nitrate) melts

    Science.gov (United States)

    Guchhait, Biswajit; Daschakraborty, Snehasis; Biswas, Ranjit

    2012-05-01

    Time-resolved fluorescence Stokes shift and anisotropy measurements using a solvation probe in [0.78CH3CONH2 + 0.22{f LiBr + (1-f) LiNO3}] melts reveal a strong decoupling of medium dynamics from viscosity. Interestingly, this decoupling has been found to occur at temperatures ˜50-100 K above the glass transition temperatures of the above melt at various anion concentrations (fLiBr). The decoupling is reflected via the following fractional viscosity dependence (η) of the measured average solvation and rotation times (⟨τs⟩ and ⟨τr⟩, respectively): ⟨τx⟩ ∝ (η/T)p (x being solvation or rotation), with p covering the range, 0.20 < p < 0.70. Although this is very similar to what is known for deeply supercooled liquids, it is very surprising because of the temperature range at which the above decoupling occurs for these molten mixtures. The kinship to the supercooled liquids is further exhibited via p which is always larger for ⟨τr⟩ than for ⟨τs⟩, indicating a sort of translation-rotation decoupling. Multiple probes have been used in steady state fluorescence measurements to explore the extent of static heterogeneity. Estimated experimental dynamic Stokes shift for coumarin 153 in these mixtures lies in the range, 1000 < Δνt/cm-1 < 1700, and is in semi-quantitative agreement with predictions from our semi-molecular theory. The participation of the fluctuating density modes at various length-scales to the observed solvation times has also been investigated.

  14. Temperature variations in Greenland from 10 to 110 kyr b2k derived from the NGRIP ice core

    Science.gov (United States)

    Kindler, Philippe; Leuenberger, Markus; Landais, Amaelle; Guillevic, Myriam

    2013-04-01

    During the last ice age dramatic temperature variations of up to 16 °C took place in Greenland which are now known as Dansgaard-Oeschger-events (DO-events). They most probably originate from the North Atlantic oceanic and atmospheric circulation system and are characterised by an abrupt warming within decades followed by a gradual cooling over hundreds to thousands of years. We have determined local temperature variations for DO-event 1 to 25 in Greenland based on δ15N measurements from the NorthGRIP ice core, corresponding to the period from 10 to 110 kyr b2k. The record is a composite of measurements from two laboratories, Laboratoire des Sciences du Climat et de l'Environnement, Paris (DO 18 to 25) and the Climate and Environmental Physics Division of the Physics Institute of the University of Bern (DO 1 to 17) with new measurements from the beginning of the Holocene to DO 8. Temperature variations were reconstructed by reproducing the measured 15N/14N ratio of air enclosed in ice bubbles by the firn densification and heat diffusion model from Schwander. The reconstruction show temperature amplitudes for the DO-events ranging from 5 to 16 °C, thereby the corresponding rates of change can exceed 0.5 °C/decade. In order get an agreement between measured δ15N, Δdepth and Δage values with their modelled analogues, a lower accumulation rate than the one associated with the used ss09sea06bm1 time scale had to be assumed. We had to reduce the accumulation rate time dependently by 0 to nearly 40% with a mean reduction over the whole time period of 16%. With these adjustments both the Δdepth and the Δage values agree between model and measurements.

  15. Effect of prior creep at 1365 K on the room temperature tensile properties of several oxide dispersion strengthened alloys

    Science.gov (United States)

    Whittenberger, J. D.

    1977-01-01

    An experimental study was conducted to determine whether oxide dispersion-strengthened (ODS) Ni-base alloys in wrought bar form are subject to creep degradation effects similar to those found in thin-gage sheet. The bar products evaluated included ODS-Ni, ODS-NiCr, and advanced ODS-NiCrAl types; the alloys included microstructures ranging from an essentially perfect single crystal to a structure consisting of very small elongated grains. Tensile test specimens were exposed to creep at various stress levels at 1365 K and then tensile tested at room temperature. Low residual tensile properties, change in fracture mode, appearance of dispersoid free bands, grain boundary cavitation, and/or internal oxidation are interpreted as creep degradation effects. The amount of degradation depends on creep strain, and degradation appears to be due to diffusional creep which produces dispersoid free bands around grain boundaries acting as vacancy sources.

  16. Magic angle spinning NMR below 6 K with a computational fluid dynamics analysis of fluid flow and temperature gradients.

    Science.gov (United States)

    Sesti, Erika L; Alaniva, Nicholas; Rand, Peter W; Choi, Eric J; Albert, Brice J; Saliba, Edward P; Scott, Faith J; Barnes, Alexander B

    2017-11-11

    We report magic angle spinning (MAS) up to 8.5 kHz with a sample temperature below 6 K using liquid helium as a variable temperature fluid. Cross polarization 13C NMR spectra exhibit exquisite sensitivity with a single transient. Remarkably, 1H saturation recovery experiments show a 1H T1 of 21 s with MAS below 6 K in the presence of trityl radicals in a glassy matrix. Leveraging the thermal spin polarization available at 4.2 K versus 298 K should result in 71 times higher signal intensity. Taking the 1H longitudinal relaxation into account, signal averaging times are therefore predicted to be expedited by a factor of >500. Computer assisted design (CAD) and finite element analysis were employed in both the design and diagnostic stages of this cryogenic MAS technology development. Computational fluid dynamics (CFD) models describing temperature gradients and fluid flow are presented. The CFD models bearing and drive gas maintained at 100 K, while a colder helium variable temperature fluid stream cools the center of a zirconia rotor. Results from the CFD were used to optimize the helium exhaust path and determine the sample temperature. This novel cryogenic experimental platform will be integrated with pulsed dynamic nuclear polarization and electron decoupling to interrogate biomolecular structure within intact human cells. Copyright © 2017. Published by Elsevier Inc.

  17. Complex permittivity of lanthanum aluminate in the 20 to 300 K temperature range from 26.5 to 40.0 GHz

    Science.gov (United States)

    Miranda, F. A.; Gordon, W. L.; Bhasin, K. B.; Ebihara, B. T.; Heinen, V. O.; Chorey, C. M.

    1990-01-01

    Dielectric constants of microwave substrates are required in the design of superconducting microwave circuits at various temperatures. In this paper, the results are reported of a study of the complex permittivity of the newly developed lanthanum aluminate (LaAlO3) substrate, in the 20 to 300 K temperature range at frequencies from 26.5 to 40.0 GHz. The value of the complex permittivity was obtained by measuring the sample scattering parameters using a microwave waveguide technique. It is observed that, while the dielectric constant did not change appreciably with frequency, its value decreased by approximately 14 percent from room temperature to 20 K.

  18. Measurement of ion temperature and flow velocity by using LIF and electric probe methods in K2H and DiPS propulsion simulators

    Science.gov (United States)

    Choi, Geun-Sig; Chung, Kyu-Sun; Woo, Hyun-Jong; Seo, Young Jun; Lee, Myoung-Jae; Lho, Taihyeop; Jung, Yong Ho; Lee, Bong Ju

    2006-10-01

    Ion temperature, plasma flow velocity and plasma density are measured in DiPS (Diversified Plasma Simulator) and K2H (KBSI-KAIST-Hanyang University) propulsion simulators by a laser induced fluorescence (LIF) method and a fast scanning electric probe system, which consists of an rf-compensated single probe and a Mach probe. In both devices helicon plasmas were stably generated with m=+1 right-helical antenna at 13.56 MHz with powers of 1 - 3kW (DiPS) and 0.5 - 1kW (K2H), and open ended magnetic configurations are utilized. The measured plasma parameters are as follows: plasma densities of 10^11 -- 10^13 cm-3 (K2H) and 10^12 -- 10^13 cm-3 (DiPS), electron temperatures of 3 -- 9 eV (K2H) and 2 -- 4 eV (DiPS), ion temperatures of 0.14 -- 0. 17 eV (K2H) and 0.05 -- 0.2 eV (DiPS) and drift velocities of 0.8 -- 1.6 km/s (k2H) and 0.2 -- 0.5 km/s (DiPS).

  19. Response of branchial Na(+)/K(+) ATPase to changes in ambient temperature in Atlantic cod (Gadus morhua) and whiting (Merlangius merlangus).

    Science.gov (United States)

    Michael, Katharina; Koschnick, Nils; Pörtner, Hans-O; Lucassen, Magnus

    2016-05-01

    The maintenance of ion and pH homeostasis despite changes in ambient temperature is crucial for ectothermic organisms. Thermal sensitivity of Na(+)/K(+) ATPase mRNA expression, protein expression and activity was determined in gills of North Sea cod (NC) and Northeastern Arctic cod (NEAC), acclimated for 6 weeks at 4 and 10 °C and compared to field samples of North Sea cod (sNC), acclimatized to early spring (4 °C) and summer (18 °C) conditions. The same analyses were conducted in gills of the confamiliar whiting, acclimated at 4 and 10 °C. Branchial Na(+)/K(+) ATPase capacities remained uncompensated at functional and protein levels in NC and NEAC at both acclimation temperatures. Na(+)/K(+) ATPase mRNA expression in NEAC acclimated at 10 °C was about twofold higher compared to NC, indicating some population-specific differentiation at this level. Lower Na(+)/K(+) ATPase capacities in gills of warm-acclimatized sNC at common assay temperatures indicate thermal compensation between seasonal extremes, and post-translational modifications contributed to this mitigation at high assay temperature. Together, cod compensates Na(+)/K(+) ATPase capacities on the warm edge of the thermal window and below 4 °C, respectively. In contrast, whiting Na(+)/K(+) ATPase capacities were cold compensated at 4 °C, supported by 1.5-fold higher mRNA and protein expression. Besides, capacities were lower in whiting compared to NC and NEAC at optimum temperature, which may be advantageous in terms of reduced maintenance cost, but at temperatures ≤4 °C, compensation may represent an energy trade-off to maintain homeostasis. The species-specific response of gadid Na(+)/K(+) ATPase indicates certain threshold temperatures beyond which compensation of the pump is elicited, possibly related to the different biogeography of these species.

  20. Vitamin K 3 family members - Part II: Single crystal X-ray structures, temperature-induced packing polymorphism, magneto-structural correlations and probable anti-oncogenic candidature

    Science.gov (United States)

    Rane, Sandhya; Ahmed, Khursheed; Salunke-Gawali, Sunita; Zaware, Santosh B.; Srinivas, D.; Gonnade, Rajesh; Bhadbhade, Mohan

    2008-12-01

    Temperature-induced packing polymorphism is observed for vitamin K 3 (menadione, 3-methyl-1,4-naphthoquinone, 1). Form 1a crystallizes at 300 K and 1b at 277 K both in the same space group P2 1/ c. Form 1b contains one molecule per asymmetric unit, performing anisotropy in g-factor viz. g z = 2.0082, g y = 2.0055 and g x = 2.0025, whereas form 1a contains two molecules in its asymmetric unit. Vitamin K 3 family members 2, [2-hydroxy vitamin K 3] and 3, [2-hydroxy-1-oximino vitamin K 3] also perform intrinsic neutral active naphthosemiquinone valence tautomers even in dark having spin concentrations due to hydrogen bonding and aromatic stacking interactions which are compared to vitamin K 3. The significant lateral C-H⋯O and O-H⋯π bifurcated or π-π ∗ interactions are discussed for molecular associations and radical formations. X-ray structure of 3 revealed π-π ∗ stack dimers as radicals signatured in EPR as triplet with five hyperfine splits [ Ā( 14N) = 11.9 G]. The centrosymmetric biradicals in 3 show diamagnetism at high temperature but below 10 K it shows paramagnetism with μeff as 0.19 B.M. Vitamin K 3 and its family members inhibit biological activities of acid phosphatase ( APase), which are proportional to their spin concentrations. This may relate to their probable anti-oncogenic candidature in future.

  1. Design of a self-aligned, wide temperature range (300 mK-300 K) atomic force microscope/magnetic force microscope with 10 nm magnetic force microscope resolution

    Energy Technology Data Exchange (ETDEWEB)

    Karcı, Özgür [NanoMagnetics Instruments Ltd., Hacettepe - İvedik OSB Teknokent, 1368. Cad., No: 61/33, 06370, Yenimahalle, Ankara (Turkey); Department of Nanotechnology and Nanomedicine, Hacettepe University, Beytepe, 06800 Ankara (Turkey); Dede, Münir [NanoMagnetics Instruments Ltd., Hacettepe - İvedik OSB Teknokent, 1368. Cad., No: 61/33, 06370, Yenimahalle, Ankara (Turkey); Oral, Ahmet, E-mail: orahmet@metu.edu.tr [Department of Physics, Middle East Technical University, 06800 Ankara (Turkey)

    2014-10-01

    We describe the design of a wide temperature range (300 mK-300 K) atomic force microscope/magnetic force microscope with a self-aligned fibre-cantilever mechanism. An alignment chip with alignment groves and a special mechanical design are used to eliminate tedious and time consuming fibre-cantilever alignment procedure for the entire temperature range. A low noise, Michelson fibre interferometer was integrated into the system for measuring deflection of the cantilever. The spectral noise density of the system was measured to be ~12 fm/√Hz at 4.2 K at 3 mW incident optical power. Abrikosov vortices in BSCCO(2212) single crystal sample and a high density hard disk sample were imaged at 10 nm resolution to demonstrate the performance of the system.

  2. Dissemination of ultraprecise measurements in radiometry and remote sensing within 100-3500K temperature range based on blackbody sources developed in VNIIOFI

    Science.gov (United States)

    Sapritsky, Victor I.; Ogarev, Sergey A.; Khlevnoy, Boris B.; Samoylov, Mikhail L.; Khromchenko, Vladimir B.; Morozova, Svetlana P.

    2002-12-01

    The large variety of high-precision unique blackbody sources: those operating at fixed temperatures provided by phase transitions of metals and metal-carbon eutectics, and variable-temperature ones had been designed in VNIIOFI for high-precision radiometry, radiation thermometry and spaceborne remote sensing within a 100 to 3500K temperature range. Paper reviews the blackbodies (BBs) ranged to low, middle and high temperatures, and describes spectral radiance and irradiance calibration facilities on the base of these BBs in IR and V-UV spectral ranges. The latest investigations of high-temperature fix-points based on metal-carbon eutectics Re-C (2748K) demonstrated an excellent reproducibility of freezing plateau (up to 0.01% in terms of radiation temperature) between series of measurements/crucibles, and about 0.003% within a sample measurement session, i.e. better than 100mK. Further Re-C (spectral irradiance measurements) and TiC-C (3057° C) eutectics are being investigated for use as high-stable radiance/irradiance sources above the conventionally assigned values of temperatures of ITS-90.

  3. Alternating current calorimeter for specific heat capacity measurements at temperatures below 10 K and pressures up to 10 GPa

    Energy Technology Data Exchange (ETDEWEB)

    Umeo, Kazunori, E-mail: kumeo@sci.hiroshima-u.ac [Cryogenics and Instrumental Analysis Division, N-BARD, Hiroshima University, Kagamiyama 1-3-1, Higashi-Hiroshima 739-8526 (Japan)

    2016-06-15

    A developed alternating current calorimeter for measuring the absolute value of specific heat C of a very small sample under a pressure up to 10 GPa and low temperature below 10 K is described. A Bridgman anvil cell made of tungsten carbide with a top diameter of 3 mm is used. A hollow at the top prevents expansion of the sample space over the anvil top. Two chip resistors, which act as a thermometer and a heater, are mounted on the outer part of a copper–beryllium gasket with a frying pan-like shape. Thus, the thermometer is not pressurized. In order to isolate the gasket from the anvil thermally, diamond powder with a grain size of 0.25 μm is placed on the anvil top. Two jumps of C at the superconducting transitions of Pb (3.3 mg) and In (5.0 mg) are observed under various pressures up to 9 GPa, as clearly as those at the ambient pressure.

  4. UV superconducting nanowire single-photon detectors with high efficiency, low noise, and 4 K operating temperature.

    Science.gov (United States)

    Wollman, E E; Verma, V B; Beyer, A D; Briggs, R M; Korzh, B; Allmaras, J P; Marsili, F; Lita, A E; Mirin, R P; Nam, S W; Shaw, M D

    2017-10-30

    For photon-counting applications at ultraviolet wavelengths, there are currently no detectors that combine high efficiency (> 50%), sub-nanosecond timing resolution, and sub-Hz dark count rates. Superconducting nanowire single-photon detectors (SNSPDs) have seen success over the past decade for photon-counting applications in the near-infrared, but little work has been done to optimize SNSPDs for wavelengths below 400 nm. Here, we describe the design, fabrication, and characterization of UV SNSPDs operating at wavelengths between 250 and 370 nm. The detectors have active areas up to 56 μm in diameter, 70 - 80% efficiency at temperatures up to 4.2 K, timing resolution down to 60 ps FWHM, blindness to visible and infrared photons, and dark count rates of ∼ 0.25 counts/hr for a 56 μm diameter pixel. These performance metrics make UV SNSPDs ideal for applications in trapped-ion quantum information processing, lidar studies of the upper atmosphere, UV fluorescent-lifetime imaging microscopy, and photon-starved UV astronomy.

  5. Temperature dependence and kinetic isotope effects for the OH + HBr reaction and H/D isotopic variants at low temperatures (53-135 K) measured using a pulsed supersonic Laval nozzle flow reactor.

    Science.gov (United States)

    Mullen, Christopher; Smith, Mark A

    2005-05-05

    The reactions of OH + HBr and all isotopic variants have been measured in a pulsed supersonic Laval nozzle flow reactor between 53 and 135 K, using a pulsed DC discharge to create the radical species and laser induced fluorescence on the A 2sigma HBr) = (10.84 +/- 0.31) x 10(-12) (T/298)(-0.67+/-0.02) cm3/s, k2 (OD + HBr) = (6.43 +/- 2.60) x 10(-12) (T/298)(-1.19+/-0.26) cm3/s, k3 (OH + DBr) = (5.89 +/- 1.93) x 10(-12) (T/298)(-0.76+/-0.22) cm3/s, and k4 (OD + DBr) = (4.71 +/- 1.56) x 10(-12) (T/298)(-1.09+/-0.21) cm3/s. A global fit of k vs T over the temperature range 23-360 K, including the new OH + HBr data, yields kT = (1.06 +/- 0.02) x 10(-11) (T/298)(-0.90+/-0.11) cm3/s, and (0.96 +/- 0.02) x 10(-11) (T/298)(-0.90+/-0.03) exp((-2.88+/-1.82 K)/T) cm3/s, in accord with previous fits. In addition, the primary and secondary kinetic isotope effects are found to be independent of temperature within experimental error over the range investigated and take on the value of (kH/kD)(AVG) = 1.64 for the primary effect and (kH/kD)(AVG) = 0.87 for the secondary effect. These results are discussed within the context of current experimental and theoretical work.

  6. Temperature-dependent quantum efficiency degradation of K-Cs-Sb bialkali antimonide photocathodes grown by a triple-element codeposition method

    Science.gov (United States)

    Ding, Zihao; Karkare, Siddharth; Feng, Jun; Filippetto, Daniele; Johnson, Matthew; Virostek, Steve; Sannibale, Fernando; Nasiatka, James; Gaowei, Mengjia; Sinsheimer, John; Muller, Erik; Smedley, John; Padmore, Howard

    2017-11-01

    K-Cs-Sb bialkali antimonide photocathodes grown by a triple-element codeposition method have been found to have excellent quantum efficiency (QE) and outstanding near-atomic surface smoothness and have been employed in the VHF gun in the Advanced Photoinjector Experiment (APEX), however, their robustness in terms of their lifetime at elevated photocathode temperature has not yet been investigated. In this paper, the relationship between the lifetime of the K-Cs-Sb photocathode and the photocathode temperature has been investigated. The origin of the significant QE degradation at photocathode temperatures over 70 °C has been identified as the loss of cesium atoms from the K-Cs-Sb photocathode, based on the in situ x-ray analysis on the photocathode film during the decay process. The findings from this work will not only further the understanding of the behavior of K-Cs-Sb photocathodes at elevated temperature and help develop more temperature-robust cathodes, but also will become an important guide to the design and operation of the future high-field rf guns employing the use of such photocathodes.

  7. Salt effect in the solubility of hydrogen in n-alcohols at pressures up to 10 MPa and temperatures up to 498.15 K

    Directory of Open Access Journals (Sweden)

    J. V.H. d’Angelo

    2000-12-01

    Full Text Available Gas-liquid solubility of hydrogen in methanol and ethanol systems with electrolytes was studied in the temperature range from 305.15 K to 498.15 K and pressures from 4 to 10 MPa. The experimental method used was the Total Pressure Method, which eliminates sampling and analysis of the phases, determining their composition at equilibrium using the following experimental data: moles of solute and solvent in the system; pressure, temperature and volume of the system at equilibrium; together with thermodynamic equations for fluid-phase equilibria. The salts used were lithium chloride and potassium acetate. The solubility of hydrogen increases with increasing temperature and pressure and the presence of salts causes a decrease in the solubility of hydrogen, when compared with the results of systems without salts, characterizing a "salting-out" effect, which is greater in conditions of lower temperature and pressure, specially for potassium acetate.

  8. Raman scattering of 2H-MoS2 at simultaneous high temperature and high pressure (up to 600 K and 18.5 GPa

    Directory of Open Access Journals (Sweden)

    JianJun Jiang

    2016-03-01

    Full Text Available The Raman spectroscopy of natural molybdenite powder was investigated at simultaneous conditions of high temperature and high pressure in a heatable diamond anvil cell (DAC, to obtain the temperature and pressure dependence of the main Raman vibrational modes (E1g, E 2 g 1 ,A1g, and 2LA(M. Over our experimental temperature and pressure range (300–600 K and 1 atm−18.5 GPa, the Raman modes follow a systematic blue shift with increasing pressure, and red shift with increasing temperature. The results were calculated by three-variable linear fitting. The mutual correlation index of temperature and pressure indicates that the pressure may reduce the temperature dependence of Raman modes. New Raman bands due to structural changes emerged at about 3–4 GPa lower than seen in previous studies; this may be caused by differences in the pressure hydrostaticity and shear stress in the sample cell that promote the interlayer sliding.

  9. Luminescence of the (O2(a(1)Δ(g)))2 collisional complex in the temperature range of 90-315 K: Experiment and theory.

    Science.gov (United States)

    Zagidullin, M V; Pershin, A A; Azyazov, V N; Mebel, A M

    2015-12-28

    Experimental and theoretical studies of collision induced emission of singlet oxygen molecules O2(a(1)Δg) in the visible range have been performed. The rate constants, half-widths, and position of peaks for the emission bands of the (O2(a(1)Δg))2 collisional complex centered around 634 nm (2) and 703 nm (3) have been measured in the temperature range of 90-315 K using a flow-tube apparatus that utilized a gas-liquid chemical singlet oxygen generator. The absolute values of the spontaneous emission rate constants k2 and k3 are found to be similar, with the k3/k2 ratio monotonically decreasing from 1.1 at 300 K to 0.96 at 90 K. k2 slowly decreases with decreasing temperature but a sharp increase in its values is measured below 100 K. The experimental results were rationalized in terms of ab initio calculations of the ground and excited potential energy and transition dipole moment surfaces of singlet electronic states of the (O2)2 dimole, which were utilized to compute rate constants k2 and k3 within a statistical model. The best theoretical results reproduced experimental rate constants with the accuracy of under 40% and correctly described the observed temperature dependence. The main contribution to emission process (2), which does not involve vibrational excitation of O2 molecules at the ground electronic level, comes from the spin- and symmetry-allowed 1(1)Ag←(1)B3u transition in the rectangular H configuration of the dimole. Alternatively, emission process (3), in which one of the monomers becomes vibrationally excited in the ground electronic state, is found to be predominantly due to the vibronically allowed 1(1)Ag←2(1)Ag transition induced by the asymmetric O-O stretch vibration in the collisional complex. The strong vibronic coupling between nearly degenerate excited singlet states of the dimole makes the intensities of vibronically and symmetry-allowed transitions comparable and hence the rate constants k2 and k3 close to one another.

  10. Temperature-(208–318 K and pressure-(18–696 Torr dependent rate coefficients for the reaction between OH and HNO3

    Directory of Open Access Journals (Sweden)

    K. Dulitz

    2018-02-01

    Full Text Available Rate coefficients (k5 for the title reaction were obtained using pulsed laser photolytic generation of OH coupled to its detection by laser-induced fluorescence (PLP–LIF. More than 80 determinations of k5 were carried out in nitrogen or air bath gas at various temperatures and pressures. The accuracy of the rate coefficients obtained was enhanced by in situ measurement of the concentrations of both HNO3 reactant and NO2 impurity. The rate coefficients show both temperature and pressure dependence with a rapid increase in k5 at low temperatures. The pressure dependence was weak at room temperature but increased significantly at low temperatures. The entire data set was combined with selected literature values of k5 and parameterised using a combination of pressure-dependent and -independent terms to give an expression that covers the relevant pressure and temperature range for the atmosphere. A global model, using the new parameterisation for k5 rather than those presently accepted, indicated small but significant latitude- and altitude-dependent changes in the HNO3 ∕ NOx ratio of between −6 and +6 %. Effective HNO3 absorption cross sections (184.95 and 213.86 nm, units of cm2 molecule−1 were obtained as part of this work: σ213.86  =  4.52−0.12+0.23  ×  10−19 and σ184.95  =  1.61−0.04+0.08  ×  10−17.

  11. Monitoring Groundwater Temperatures in a Shallow Urban Aquifer Before, During and After Installation of a Ground Source Heat System in Cardiff, U.K.

    Science.gov (United States)

    Patton, Ashley M.; Farr, Gareth J.; Boon, David P.; James, David R.; Williams, Bernard; Tucker, David; Harcombe, Gareth

    2016-04-01

    Exploitation of shallow urban aquifers, warmed by the Urban Heat Island Effect, is a relatively new concept in the U.K. An extensive groundwater temperature baseline monitoring network has been established for a shallow superficial aquifer in the city of Cardiff, U.K., to characterise groundwater temperatures and monitor the impacts of the first open-loop ground source heat pump (GSHP) installed in the city. In Spring 2014, temperature profiling was carried out at 1m depth intervals at 168 groundwater monitoring boreholes across Cardiff, establishing baseline groundwater temperatures within the shallow (Data was contoured to form the first U.K. 2D city heat map. During the warmest time of year, Autumn 2014, a subset of boreholes were re-profiled to ascertain seasonal temperature variation, defining the Zone of Seasonal Fluctuation. Re-profiling was again carried out at these boreholes in Autumn 2015 to confirm these temperatures as normal for that time of year. By comparing Spring and Autumn profiles, the average depth to the base of the Zone of Seasonal Fluctuation was found to be 9.5mbgl. Two >100m boreholes showed the urban warming effect may extend to 80mbgl, before temperatures follow the predicted geothermal gradient. We term this the Zone of Anthropogenic Influence. After initial baseline temperatures were established, a site was selected for the installation of a shallow GSHP. Before installation work began, a monitoring network was set up to establish a temperature baseline for future GSHPs and identify any impacts on the thermal resource caused by removing ~2°C from the abstracted groundwater prior to reinjection into the aquifer. This comprised of 97 temperature loggers in 60 boreholes, including the abstraction and recharge boreholes and boreholes up and down gradient of the site. Some of these boreholes have multiple loggers at different depths, including the near-surface, but the majority of loggers were placed within the boreholes' slotted sections

  12. Dependence of the four-atom reaction HBr + OH → Br + H2O on temperatures between 20 and 2000 K.

    Science.gov (United States)

    Ree, J; Kim, Y H; Shin, H K

    2015-04-02

    A quasiclassical trajectory method is used to study the temperature dependence of HBr + OH → Br + H2O using analytic forms of two-, three-, and four-body and long-range interaction potentials. Below 300 K, the reaction is attraction-driven and occurs through formation of a collision complex BrH···OH, which is sufficiently long-lived to enhance H atom tunneling. Strong negative temperature dependence of the complex-mode rate is found between 20 and 300 K, consistent with experimental data reported by various authors. Above 300 K, the reaction occurs primarily through a direct-reaction mechanism. The sum of the complex- and direct-mode rates is shown to describe the reaction over the wide range 20-2000 K. The primary kinetic isotope effect is nearly constant with the normal H reaction faster by a factor of ∼1.7 over the entire temperature range. The product energy distribution in vibration, rotation, and translation at 300 K is found to be 48, 8, and 44%, respectively. The 1:1 resonance leads to efficient flow of energy between the stretching modes. Less than a quarter of the H2O vibrational energy deposits in the bending mode through intramolecular flow from the two stretching modes.

  13. Spontaneous ignition in afterburner segment tests at an inlet temperature of 1240 K and a pressure of 1 atmosphere with ASTM jet-A fuel

    Science.gov (United States)

    Schultz, D. F.; Branstetter, J. R.

    1973-01-01

    A brief testing program was undertaken to determine if spontaneous ignition and stable combustion could be obtained in a jet engine afterburning operating with an inlet temperature of 1240 K and a pressure of 1 atmosphere with ASTM Jet-A fuel. Spontaneous ignition with 100-percent combustion efficiency and stable burning was obtained using water-cooled fuel spraybars as flameholders.

  14. Investigation of oxygen disorder, thermal parameters, lattice vibrations and elastic constants of UO2 and ThO2 at temperatures up to 2 930 K

    DEFF Research Database (Denmark)

    Clausen, Kurt Nørgaard; Hayes, W; Hutchings, M.T.

    1984-01-01

    A knowledge of the thermodynamic properties of UO2 at temperatures in the region 1 500-3 100 K is of importance in reactor safety calculations, yet there are relatively few detailed experimental data available. In particular the major question of whether Frenkel disorder occurs in UO2 at high tem...

  15. Investigation of luminescence and scintillation properties of a ZnS-Ag/{sup 6}LiF scintillator in the 7-295 K temperature range

    Energy Technology Data Exchange (ETDEWEB)

    Mikhailik, V.B., E-mail: v.mikhailik@physics.ox.ac.uk [Department of Physics, University of Oxford, Keble Road, Oxford OX1 3RH (United Kingdom); Diamond Light Source, Harwell Science Campus, Didcot OX11 0DE (United Kingdom); Henry, S.; Horn, M.; Kraus, H.; Lynch, A.; Pipe, M. [Department of Physics, University of Oxford, Keble Road, Oxford OX1 3RH (United Kingdom)

    2013-02-15

    The luminescence and scintillation properties of ZnS-Ag/{sup 6}LiF where studied in the 7-295 K temperature range to evaluate the suitability of the scintillator for neutron detection at very low temperature (<1 K). It is shown that decrease of temperature has little effect upon principal luminescence and scintillation characteristics of ZnS-Ag: the changes of emission intensity are small for photoexcitation and negligible for excitation with {alpha}-particles. The recombination kinetics of the scintillation decay exhibits modest shortening of the fast decay time constant, from 4.52 to 3.35 {mu}s with cooling to 10 K. It is concluded that ZnS-Ag/{sup 6}LiF is a promising scintillator for cryogenic application. - Highlights: Black-Right-Pointing-Pointer Luminescence and scintillations of ZnS-Ag/6LiF neutron scintillator are studied over 7-295 K. Black-Right-Pointing-Pointer Interpretation of excitation spectra is offered. Black-Right-Pointing-Pointer Scintillation properties exhibit little changes with cooling. Black-Right-Pointing-Pointer ZnS-Ag/6LiF can be used as neutron scintillation detector at cryogenic temperatures.

  16. Analysis and Experiment of Hot-Spot Temperature Rise of 110 kV Three-Phase Three-Limb Transformer

    Directory of Open Access Journals (Sweden)

    Ruohan Gong

    2017-07-01

    Full Text Available This paper presents a fluid-thermal coupled analysis method to compute the temperature distribution in a 31.5 MVA/110 kV oil natural air natural (ONAN three-phase three-limb transformer. The power losses of windings and core are measured by load-loss test and no-load test respectively. The convective heat transfer process, radiation and oil flow inside the transformer are investigated by finite volume method (FVM. In order to validate the feasibility and accuracy of the presented method, the temperature measuring system based on fiber Brag grating (FBG sensor is constructed for the temperature rise test of the 31.5 MVA/110 kV ONAN transformer. The simulation results deduced from the proposed method agree well with experimental data. This model can be applied to optimizing design and load scheduling.

  17. Experimental study of high-temperature properties of zirconium carbide as a protective material for nuclear power and aerospace technologies (from 2000 to 5000 K)

    Science.gov (United States)

    Savvatimskiy, A. I.; Onufriev, S. V.; Muboyadzhyan, S. A.; Seredkin, N. N.

    2017-11-01

    The temperature dependences of the thermal and electro physical properties of the zirconium carbide ZrC + C and ZrCa0.95 were studied in the temperature range 2000-5000 K. The Zr+C specimens were in the form of thin layers sputtered on quarts substrate and ZrC0.95 specimens were in the form of plates cut off from the sintered block. The properties are measured: temperature and heat of fusion, enthalpy, specific heat and resistivity, referred to the initial dimensions. A steep increase in the specific heat of these substances before melting and a sharp decrease after melting were observed at a heating rate of ∼ 108 K/s, which is possibly due to the formation of Frenkel pair defects in the specimens.

  18. Low-damage plasma etching of porous low-k films in CF3Br and CF4 plasmas under low-temperature conditions

    Science.gov (United States)

    Miakonkikh, A.; Clemente, I.; Vishnevskiy, A.; Rudenko, K.; Baklanov, M.

    2016-12-01

    Low temperature etching of organosilicate low-k dielectrics in CF3Br and CF4 plasmas is studied. Chemical composition if pristine film and etched were measured by FTIR. Decrease in plasma-induced damage under low-temperature conditions is observed. It is shown that the plasma damage reduction is related to accumulation of reaction products. The reaction products could be removed by thermal bake. In the case of CF4 plasma, the thickness of CFx polymer increases with the temperature reduction. This polymer layer leads to strong decrease of diffusion rate of fluorine atoms and as a consequence to reduction of plasma-induced damage (PID). Bromine containing reaction products are less efficient for low-k surface protection against the plasma damage.

  19. Measurement of Thermal Conductivities of Two Cryoprotective Agent Solutions for Vitreous Cryopreservation of Organs at the Temperature Range of 77 K-300 K Using a Thermal Sensor Made of Microscale Enamel Copper Wire.

    Science.gov (United States)

    Li, Yufang; Zhao, Gang; Hossain, S M Chapal; Panhwar, Fazil; Sun, Wenyu; Kong, Fei; Zang, Chuanbao; Jiang, Zhendong

    2017-06-01

    Biobanking of organs by cryopreservation is an enabling technology for organ transplantation. Compared with the conventional slow freezing method, vitreous cryopreservation has been regarded to be a more promising approach for long-term storage of organs. The major challenges to vitrification are devitrification and recrystallization during the warming process, and high concentrations of cryoprotective agents (CPAs) induced metabolic and osmotic injuries. For a theoretical model based optimization of vitrification, thermal properties of CPA solutions are indispensable. In this study, the thermal conductivities of M22 and vitrification solution containing ethylene glycol and dimethyl sulfoxide (two commonly used vitrification solutions) were measured using a self-made microscaled hot probe with enameled copper wire at the temperature range of 77 K-300 K. The data obtained by this study will further enrich knowledge of the thermal properties for CPA solutions at low temperatures, as is of primary importance for optimization of vitrification.

  20. Design and production of efficient current leads for 1500-A, 50-Hz service in a 77-4 K temperature gradient

    Energy Technology Data Exchange (ETDEWEB)

    Balachandran, U.; Youngdahl, C.A.; Lanagan, M.T. [and others

    1994-10-01

    Two arrays of BSCCO 2223 bars were designed and produced for use in current leads for a power utility fault-current limiter operating at 4 K. Each conduction-cooled array, consisting of four parallel bars arranged within a 100-mm-diameter boundary, delivered 1,500 A peak, 50-Hz AC through a 77-4 K temperature gradient while dissipating < 0.2 W. The sinter-forged bars displayed DC critical current densities of 950--1,300 A/cm{sup 2} at 77 K and > 5,000 A/cm{sup 2} at 4 K. Magnetic field sensitivity was relatively low. Thermal conductivity tests showed values higher than literature values for polycrystalline BSCCO 2223 made by other processes.

  1. Measurement of the (pressure, density, temperature) relation of two (methane + nitrogen) gas mixtures at temperatures between 240 and 400 K and pressures up to 20 MPa using an accurate single-sinker densimeter

    Energy Technology Data Exchange (ETDEWEB)

    Chamorro, C.R. [Grupo de Termodinamica y Calibracion (TERMOCAL), Dpto. Ingenieria Energetica y Fluidomecanica, E.T.S. de Ingenieros Industriales, Universidad de Valladolid, E-47071 Valladolid (Spain)]. E-mail: cescha@eis.uva.es; Segovia, J.J. [Grupo de Termodinamica y Calibracion (TERMOCAL), Dpto. Ingenieria Energetica y Fluidomecanica, E.T.S. de Ingenieros Industriales, Universidad de Valladolid, E-47071 Valladolid (Spain); Martin, M.C. [Grupo de Termodinamica y Calibracion (TERMOCAL), Dpto. Ingenieria Energetica y Fluidomecanica, E.T.S. de Ingenieros Industriales, Universidad de Valladolid, E-47071 Valladolid (Spain); Villamanan, M.A. [Grupo de Termodinamica y Calibracion (TERMOCAL), Dpto. Ingenieria Energetica y Fluidomecanica, E.T.S. de Ingenieros Industriales, Universidad de Valladolid, E-47071 Valladolid (Spain); Estela-Uribe, J.F. [Facultad de Ingenieria, Universidad Javeriana-Cali, Calle 18, 118-250 Cali (Colombia); Trusler, J.P.M. [Department of Chemical Engineering, Imperial College London, London SW7 2AZ (United Kingdom)

    2006-07-15

    Comprehensive (p, {rho}, T) measurements on two gas mixtures of (0.9CH{sub 4} + 0.1N{sub 2}) and (0.8CH{sub 4} + 0.2N{sub 2}) have been carried out at six temperatures between 240 and 400 K and at pressures up to 20 MPa. A total of 108 (p, {rho}, T) data for the first mixture and 134 for the second one are given. These measurements were performed using a compact single-sinker densimeter based on Archimedes' buoyancy principle. The overall uncertainty in density {rho} is estimated to be (1.5 . 10{sup -4} . {rho} + 2 . 10{sup -3} kg . m{sup -3}) (coverage factor k = 2), the uncertainty in temperature T is estimated to be 0.006 K (coverage factor k = 2), and the uncertainty in pressure p is estimated to be 1 . 10{sup -4}.p (coverage factor k = 2). The equipment has been previously checked with pure nitrogen over the whole temperature and pressure working ranges and experimental results (35 values) are given and a comparison with the reference equation of state for nitrogen is presented.

  2. Room temperature optical and magnetic properties of (Cu, K) doped ZnO based diluted magnetic semiconductor thin films grown by chemical bath deposition method

    Science.gov (United States)

    Shanmuganathan, G.; Shameem Banu, I. B.

    2014-11-01

    ZnO based diluted magnetic semiconductor thin films were prepared by simultaneously doping the non-magnetic Cu and K in the cation sites of the host ZnO employing the chemical bath deposition method. In this study, K was kept at a concentration of 1% and Cu concentration was varied at 1%, 2%, 3% and 4%. For comparative study, 1% K doped ZnO was also prepared. The influence of K and Cu doping on the transmittance, band gap and magnetic properties were investigated. The XRD revealed that the thin films are polycrystalline and has hexagonal wurtzite crystal structure of ZnO without any secondary phases. Well developed hexagonal structures are observed from the surface morphology. The transmittance shows a significant variation when Cu is incorporated at different doping levels along with K and the band gap change is significant for higher concentration. The room temperature magnetic hysteresis revealed the typical ferromagnetic behavior of K doped and (K, Cu) doped ZnO thin films. The K and Cu doped ZnO thin film exhibited enhanced magnetization compared to K doped ZnO thin film. The present study reveals that the magnetic results of the K and Cu doped ZnO are markedly better than that of the Cu doped ZnO reported by other experiments. The magnetic properties have been explained on the basis of the photoluminescence spectrum. The origin of ferromagnetism is due to the p-d hybridization which has the influence on the band gap also.

  3. A close-up of the lower part of a 13 kA current lead. The high-temperature superconductor (on the left in the photo) with the low-temperature superconductor (on the right). Resting in liquid helium, the low-temperature superconductor is connected to the bus-bars conveying the current to the LHC magnets.

    CERN Multimedia

    2004-01-01

    A close-up of the lower part of a 13 kA current lead. The high-temperature superconductor (on the left in the photo) with the low-temperature superconductor (on the right). Resting in liquid helium, the low-temperature superconductor is connected to the bus-bars conveying the current to the LHC magnets.

  4. Observing electron spin resonance between 0.1 and 67 GHz at temperatures between 50 mK and 300 K using broadband metallic coplanar waveguides

    Energy Technology Data Exchange (ETDEWEB)

    Wiemann, Yvonne; Simmendinger, Julian; Clauss, Conrad; Bogani, Lapo; Dressel, Martin; Scheffler, Marc [1. Physikalisches Institut, Universität Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart (Germany); Bothner, Daniel; Koelle, Dieter; Kleiner, Reinhold [Physikalisches Institut and Center for Collective Quantum Phenomena in LISA+, Universität Tübingen, Auf der Morgenstelle 14, 72076 Tübingen (Germany)

    2015-05-11

    We describe a fully broadband approach for electron spin resonance (ESR) experiments, where it is possible to tune not only the magnetic field but also the frequency continuously over wide ranges. Here, a metallic coplanar transmission line acts as compact and versatile microwave probe that can easily be implemented in different cryogenic setups. We perform ESR measurements at frequencies between 0.1 and 67 GHz and at temperatures between 50 mK and room temperature. Three different types of samples (Cr{sup 3+} ions in ruby, organic radicals of the nitronyl-nitroxide family, and the doped semiconductor Si:P) represent different possible fields of application for the technique. We demonstrate that an extremely large phase space in temperature, magnetic field, and frequency for ESR measurements, substantially exceeding the range of conventional ESR setups, is accessible with metallic coplanar lines.

  5. A review of the deformation behavior of tungsten at temperatures less than 0.2 of the melting point /K/

    Science.gov (United States)

    Stephens, J. R.

    1974-01-01

    The deformation behavior of tungsten at temperatures below 0.2 times the absolute melting temperature is reviewed with primary emphasis on the temperature dependence of the yield stress and the ductile-brittle transition. It is concluded that a model based on the high Peierls stress of tungsten best accounts for the observed mechanical behavior at low temperatures. Recent research suggests an important role of electron concentration and bonding on the mechanical behavior of tungsten. Future research on tungsten should include studies to define more clearly the correlation between electron concentration and mechanical behavior of alloys of tungsten and other transition metal alloys.

  6. Low-temperature anomalies of EXAFS at the K-edge of As in superconducting LaFe0.89Co0.11AsO

    Science.gov (United States)

    Bianconi, A.; Menushenkov, A. P.; Ivanov, V. G.; Ivanov, A. A.; Joseph, B.

    2017-12-01

    The temperature dependence of the EXAFS-spectra measured above the K absorption edge of As in superconducting (T c = 13.5 K) single crystals of LaFe0.89Co0.11AsO were investigated. Analysis of the spectra in the harmonic approximation revealed anomalies in the temperature dependence of the Debye-Waller factor for As-Fe interatomic bond which correlated with the temperature dependence of electrical resistivity, the coefficient of thermal expansion and magnetic susceptibility given in literature. Taking into account that similar anomalies were earlier observed in superconducting oxides based on BaBiO3 and in cuprates we conducted the EXAFS spectra analysis in the anharmonic approximation using the potential of arbitrary shape for As-Fe bond vibrations. It was shown that the double-well approximation describes the temperature dependence of the EXAFS spectra better than the harmonic one. The temperature dependence of tunneling frequency and a distance between the wells for double-well potential were obtained. The results indicate that local structural dynamic heterogeneities have a strong impact on macroscopic properties of iron-based superconductors.

  7. An adiabatic calorimeter for heat capacity measurements of polyurethane foam with blowing agent of HFC245fa in the temperature range 60-290K

    Energy Technology Data Exchange (ETDEWEB)

    Yang, C.G.; Xu, L.; Zhang, L.Q.; Chen, N. [Institute of Refrigeration and Cryogenics, Shanghai Jiao Tong University, Shanghai 200030 (China)

    2006-06-15

    In order to meet the urgent need of heat insulating materials used under low temperature in the area of aerospace, a new polyurethane (PU) foam with HFC245fa as blowing agent was developed. In this paper, the heat capacity in the temperature range of 60-290K of the new material was measured through an automated adiabatic calorimeter, which was composed of a heat insulation system, a power measuring system, a vacuum pumping system and a cooling system. The sample cell of the calorimeter was equipped with a miniature platinum thermometer surrounded by two adiabatic shields and housed in a high vacuum can. The temperature differences among the sample cell and the inner and outer adiabatic shields could be adjusted automatically to less than 0.05K, all which ensure there was no heat exchange between the sample and surroundings. Under these conditions, the mathematical formulation of the sample with the physical model was given. Through measuring the heat capacity of {alpha}-Al{sub 2}O{sub 3}, which is a standard reference material, a relatively high reliability with a deviation of +/-2.5% of this adiabatic calorimeter was shown compared with the standard data. The results indicate that the newly developed PU foam has a higher heat capacity compared with other heat insulating materials, and there is no obvious sign of any phase transition or thermal anomaly in the entire temperature range. That is to say, the material is thermodynamically stable when used in the low temperature range. (author)

  8. An adiabatic calorimeter for heat capacity measurements of polyurethane foam with blowing agent of HFC245fa in the temperature range 60-290 K

    Energy Technology Data Exchange (ETDEWEB)

    Yang, C.G. [Institute of Refrigeration and Cryogenics, Shanghai Jiao Tong University, Shanghai 200030 (China)]. E-mail: chunguang_yang@sjtu.edu.cn; Xu, L. [Institute of Refrigeration and Cryogenics, Shanghai Jiao Tong University, Shanghai 200030 (China); Zhang, L.Q. [Institute of Refrigeration and Cryogenics, Shanghai Jiao Tong University, Shanghai 200030 (China); Chen, N. [Institute of Refrigeration and Cryogenics, Shanghai Jiao Tong University, Shanghai 200030 (China)

    2006-06-15

    In order to meet the urgent need of heat insulating materials used under low temperature in the area of aerospace, a new PU foam with HFC245fa as blowing agent was developed. In this paper, the heat capacity in the temperature range of 60-290 K of the new material was measured through an automated adiabatic calorimeter, which was composed of a heat insulation system, a power measuring system, a vacuum pumping system and a cooling system. The sample cell of the calorimeter was equipped with a miniature platinum thermometer surrounded by two adiabatic shields and housed in a high vacuum can. The temperature differences among the sample cell and the inner and outer adiabatic shields could be adjusted automatically to less than 0.05 K, all which ensure there was no heat exchange between the sample and surroundings. Under these conditions, the mathematical formulation of the sample with the physical model was given. Through measuring the heat capacity of {alpha}-Al{sub 2}O{sub 3}, which is a standard reference material, a relatively high reliability with a deviation of {+-}2.5% of this adiabatic calorimeter was shown compared with the standard data. The results indicate that the newly developed PU foam has a higher heat capacity compared with other heat insulating materials, and there is no obvious sign of any phase transition or thermal anomaly in the entire temperature range. That is to say, the material is thermodynamically stable when used in the low temperature range.

  9. Insolation data manual: long-term monthly averages of solar radiation, temperature, degree-days and global anti K/sub T/ for 248 national weather service stations

    Energy Technology Data Exchange (ETDEWEB)

    Knapp, C L; Stoffel, T L; Whitaker, S D

    1980-10-01

    Monthly averaged data is presented which describes the availability of solar radiation at 248 National Weather Service stations. Monthly and annual average daily insolation and temperature values have been computed from a base of 24 to 25 years of data. Average daily maximum, minimum, and monthly temperatures are provided for most locations in both Celsius and Fahrenheit. Heating and cooling degree-days were computed relative to a base of 18.3/sup 0/C (65/sup 0/F). For each station, global anti K/sub T/ (cloudiness index) were calculated on a monthly and annual basis. (MHR)

  10. Thermodynamically complete equation of state of MgO from true radiative shock temperature measurements on samples preheated to 1850 K

    Science.gov (United States)

    Fat'yanov, O. V.; Asimow, P. D.; Ahrens, T. J.

    2018-01-01

    Plate impact experiments in the 100-250 GPa pressure range were done on a 〈100 〉 single-crystal MgO preheated before compression to 1850 K. Hot Mo(driver)-MgO targets were impacted with Mo or Ta flyers launched by the Caltech two-stage light-gas gun up to 7.5 km/s. Radiative temperatures and shock velocities were measured with 3%-4% and 1%-2% uncertainty, respectively, by a six-channel pyrometer with 3-ns time resolution, over a 500-900-nm spectral range. MgO shock front reflectivity was determined in additional experiments at 220 and 248 GPa using ≈50 /50 high-temperature sapphire beam splitters. Our measurements yield accurate experimental data on the mechanical, optical, and thermodynamic properties of B1 phase MgO from 102 GPa and 3900 K to 248 GPa and 9100 K, a region not sampled by previous studies. Reported Hugoniot data for MgO initially at ambient temperature, T =298 K, and the results of our current Hugoniot measurements on samples preheated to 1850 K were analyzed using the most general methods of least-squares fitting to constrain the Grüneisen model. This equation of state (EOS) was then used to construct maximum likelihood linear Hugoniots of MgO with initial temperatures from 298 to 2400 K. A parametrization of all EOS values and best-fit coefficients was done over the entire range of relevant particle velocities. Total uncertainties of all the EOS parameters and correlation coefficients for these uncertainties are also given. The predictive capabilities of our updated Mie-Grüneisen EOS were confirmed by (1) the good agreement between our Grüneisen data and five semiempirical γ (V ) models derived from porous shock data only or from combined static and shock data sets, (2) the very good agreement between our 1-bar Grüneisen values and γ (T ) at ambient pressure recalculated from reported experimental data on the adiabatic bulk modulus Ks(T ) , and (3) the good agreement of the brightness temperatures, corrected for shock reflectivity

  11. Vacuum properties of high quality value tuning fork in high magnetic field up to 8 Tesla and at mK temperatures

    Science.gov (United States)

    Človečko, M.; Kupka, M.; Skyba, P.; Vavrek, F.

    2014-12-01

    Tuning forks are very popular experimental tools widely applied in low and ultra low temperature physics as mechanical resonators and cantilevers in the study of quantum liquids, STM and AFM techniques, etc. As an added benefit, these forks being cooled, have very high Q-value, typically 106 and their properties seems to be magnetic field independent. We present preliminary vacuum measurements of a commercial tuning fork oscillating at frequency 32 kHz conducted in magnetic fields up to 8 T and at temperature ~ 10 mK. We found an additional weak damping of the tuning fork motion depending on magnetic field magnitude and we discuss physical nature of the observed phenomena.

  12. Low-temperature (T = 250-400 K) oxygen adsorption on YBa sub 2 Cu sub 3 O sub 6 sub . sub 9 ceramics

    CERN Document Server

    Kuznetsov, V N

    2001-01-01

    The oxygen adsorption on the YBa sub 2 Cu sub 3 O sub 6 sub . sub 9 ceramics is studied within the temperature range of 250-400 K through the method of the thermodesorption (TD) mass-spectroscopy. It is established, that depending on the temperature (T subalpha) the O sub 2 adsorption leads to formation of two (gamma 1 and gamma 2 at the T subalpha = 350 K) adsorption forms. The associative desorption mechanism with the activation energy (0.63 +- 0.08) (gamma 1) and (1.13 +- 0.02) eV (gamma 2) is the most probable one for both forms. The model, qualitatively describing the oxygen sorption on the ceramics, the initial stage whereof is constituted by the gamma 2 adsorption form formation, is proposed

  13. Reaction kinetics of (CF3)2CFCN with OH radicals as a function of temperature (278-358 K): A good replacement for greenhouse SF6?

    Science.gov (United States)

    Blázquez, Sergio; Antiñolo, María; Nielsen, Ole J.; Albaladejo, José; Jiménez, Elena

    2017-11-01

    In many industrial applications, (CF3)2CFCN has been suggested as SF6 substitute, which possess a global warming potential (GWP100-yr) of 23500 relative to CO2. The temperature dependence of the rate coefficient (kOH) for the OH + (CF3)2CFCN reaction is reported for the first time: kOH(278-358 K) = (5.9 ± 3.2) × 10-13exp{-(1856 ± 162)/T} cm3 molecule-1 s-1. A lifetime of 47 years was estimated relative to that of CH3CCl3. Infrared absorption cross sections were also determined to derive the radiative efficiency (0.28 W m-2 ppbv-1). A GWP100-yr of 3646 was estimated, resulting in a significant reduction of the contribution to global warming if SF6 was replaced by (CF3)2CFCN.

  14. Simultaneous high-pressure high-temperature elastic velocity measurement system up to 27 GPa and 1873 K using ultrasonic and synchrotron X-ray techniques

    Science.gov (United States)

    Higo, Yuji; Irifune, Tetsuo; Funakoshi, Ken-ichi

    2018-01-01

    A new pulse-echo interferometry system has been developed for measurements of sound velocity at simultaneous high pressure and temperature corresponding to those of the Earth's lower mantle, using synchrotron X-ray techniques at SPring-8. A combination of a low-noise high-frequency amplifier and a high-speed solid-state relay system allowed us to clearly detect the ultrasonic echoes of a small sample (<1.0 mm in diameter and length) in multi-anvil apparatus. A new high-pressure cell has also been introduced for precise measurement of the length of the tiny sample by X-ray radiography imaging under very high pressure and temperature. The new system was tested by measuring elastic velocities of α-Al2O3 over wide pressure and temperature ranges of up to 27 GPa and 1873 K, respectively. The resultant adiabatic bulk modulus, shear modulus, and pressure and temperature derivatives of α-Al2O3 are K0S = 251.2 (18) GPa, ∂ KS/∂ P = 4.21 (10), ∂ KS/∂ T = -0.025 (1), G = 164.1 (7), ∂ G/∂ P = 1.59 (3), ∂ G/∂ T = -0.021 (1). These values are consistent with those previously reported based on experiments at high temperatures at ambient pressure and high pressures at room temperature. The present system allows precise measurements of the elastic velocities of minerals under the pressures and temperatures corresponding to the lower mantle for the first time, which should greatly contribute to our understanding of mineralogy of the whole mantle.

  15. Measurement of (liquid + liquid) equilibria for ternary systems of (N-formylmorpholine + benzene + cyclohexane) at temperatures (303.15, 308.15, and 313.15) K

    Energy Technology Data Exchange (ETDEWEB)

    Seyedein Ghannad, S. MohammadReza [School of Chemical, Gas and Petroleum Engineering, Semnan University, Semnan 35195-363 (Iran, Islamic Republic of); Lotfollahi, Mohammad Nader, E-mail: mnlotfollahi@semnan.ac.i [School of Chemical, Gas and Petroleum Engineering, Semnan University, Semnan 35195-363 (Iran, Islamic Republic of); Haghighi Asl, Ali [School of Chemical, Gas and Petroleum Engineering, Semnan University, Semnan 35195-363 (Iran, Islamic Republic of)

    2011-06-15

    Research highlights: LLE were measured for (NFM+benzene+cyclohexane) at temperatures (303.15, 308.15 and 313.15) K. UNIQUAC and NRTL models were used to correlate the LLE. The reliability of the experimental data was tested by the Othmer-Tobias correlation. The obtained RMSDs are 0.0367 for NRTL model and 0.0539 for UNIQUAC model. - Abstract: This work demonstrates the ability of N-formylmorpholine (NFM) to act as an extraction solvent for the removal of benzene from its mixture with cyclohexane. The (liquid + liquid) equilibria (LLE) were measured for a ternary system of {l_brace}N-formylmorpholine (NFM) + benzene + cyclohexane{r_brace} under atmospheric pressure and at temperatures (303.15, 308.15, and 313.15) K. The experimental distribution coefficients (K) and selectivity factors (S) were obtained to reveal the extractive effectiveness of the solvent for separation of benzene from cyclohexane. The LLE results for the system studied indicate that increasing temperature decreases selectivity of the solvent. The reliability of the experimental results was tested by applying the Othmer-Tobias correlation. In addition, the universal quasichemical activity coefficient (UNIQUAC) and the non-random two liquids equation (NRTL) were used to correlate the LLE data using the interaction parameters determined from the experimental data. The root mean square deviations (RMSDs) obtained comparing calculated and experimental two-phase compositions are 0.0367 for the NRTL model and 0.0539 for the UNIQUAC model.

  16. Thermodynamic properties and equation of state of liquid di-isodecyl phthalate at temperature between (273 and 423) K and at pressures up to 140 MPa

    Energy Technology Data Exchange (ETDEWEB)

    Peleties, F. [Department of Chemical Engineering, Imperial College London, South Kensington Campus, London SW7 2AZ (United Kingdom); Segovia, J.J. [Grupo de Termodinamica y Calibracion (TERMOCAL), Dpto. Ingenieria Energetica y Fluidomecanica, E.T.S. de Ingenieros Industriales, Universidad de Valladolid, E-47011 Valladolid (Spain); Trusler, J.P.M., E-mail: m.trusler@imperial.ac.u [Department of Chemical Engineering, Imperial College London, South Kensington Campus, London SW7 2AZ (United Kingdom); Vega-Maza, D. [Grupo de Termodinamica y Calibracion (TERMOCAL), Dpto. Ingenieria Energetica y Fluidomecanica, E.T.S. de Ingenieros Industriales, Universidad de Valladolid, E-47011 Valladolid (Spain)

    2010-05-15

    We report measurements of the thermodynamic properties of liquid di-isodecyl phthalate (DIDP) and an equation of state determined therefrom. The speed of sound in DIDP was measured at temperatures between (293.15 and 413.15) K and a pressures between (0.1 and 140) MPa with a relative uncertainty of 0.1%. In addition, the isobaric specific heat capacity was measured at temperatures between (293.15 and 423.15) K at a pressure of 0.1 MPa with a relative uncertainty of 1%, and the density was measured at temperatures between (273.15 and 413.15) K at a pressure of 0.1 MPa with a relative uncertainty of 0.015%. The thermodynamic properties of DIDP were obtained from the measured speeds of sound by thermodynamic integration starting from the initial values of density and isobaric specific heat capacity obtained experimentally. The results have been represented by a new equation of state containing nine parameters with an uncertainty in density not worse than 0.025%. Comparisons with literature data are made.

  17. Morphotropy and temperature-driven polymorphism in A2Th(AsO4)2 (A = Li, Na, K, Rb, Cs) series.

    Science.gov (United States)

    Yu, Na; Klepov, Vladislav V; Modolo, Giuseppe; Bosbach, Dirk; Suleimanov, Evgeny V; Gesing, Thorsten M; Robben, Lars; Alekseev, Evgeny V

    2014-10-20

    A new alkaline thorium arsenate family was obtained and systematically investigated. The structures of A2Th(AsO4)2 (A = Li, Na, K, Rb, Cs) were determined from single crystal X-ray diffraction data. Li2Th(AsO4)2 and either isostructural K2Th(AsO4)2 and Rb2Th(AsO4)2 crystallize in the monoclinic crystal system. Na2Th(AsO4)2 and Cs2Th(AsO4)2 crystallize in the orthorhombic and tetragonal crystal systems, respectively. Li2Th(AsO4)2 consists of [Th(AsO4)2](2-) layers with Li atoms in the interlayer space. The rest of the compounds are based on 3D frameworks. Differences in local environments of ThO8 coordination polyhedra are described in relation to the symmetry. Despite different local environments of ThO8 coordination polyhedra and different structural symmetry, underlying nets of A2Th(AsO4)2 (A = Na, K, Rb, Cs) were shown to be the same. Single-crystal and powder Raman spectra were measured, and bands are assigned. DSC measurements showed phase transitions in K2Th(AsO4)2 and Rb2Th(AsO4)2, which were studied using high-temperature powder X-ray diffraction (HT-PXRD). The data of HT-PXRD demonstrates two high-temperature polymorphic modification of K2Th(AsO4)2 and only one for the isotypic Rb2Th(AsO4)2. The phase transitions in both K and Rb phases are reversible.

  18. Prediction of the critical reduced electric field strength for carbon dioxide and its mixtures with copper vapor from Boltzmann analysis for a gas temperature range of 300 K to 4000 K at 0.4 MPa

    Science.gov (United States)

    Li, Xingwen; Guo, Xiaoxue; Zhao, Hu; Jia, Shenli; Murphy, Anthony B.

    2015-04-01

    The influence of copper vapor mixed in hot CO2 on dielectric breakdown properties of gas mixture at a fixed pressure of 0.4 MPa for a temperature range of 300 K-4000 K is numerically analyzed. First, the equilibrium composition of hot CO2 with different copper fractions is calculated using a method based on mass action law. The next stage is devoted to computing the electron energy distribution functions (EEDF) by solving the two-term Boltzmann equation. The reduced ionization coefficient, the reduced attachment coefficient, and the reduced effective ionization coefficient are then obtained based on the EEDF. Finally, the critical reduced electric field (E/N)cr is obtained. The results indicate that an increasing mole fraction of copper markedly reduces (E/N)cr of the CO2-Cu gas mixtures because of copper's low ionization potential and large ionization cross section. Additionally, the generation of O2 from the thermal dissociation of CO2 contributes to the increase of (E/N)cr of CO2-Cu hot gas mixtures from about 2000 K to 3500 K.

  19. The effect of temperature upon the pathogenicity and chemical control of Rhizoctonia solani K. on potato tubers (Solanum tuberosum L.

    Directory of Open Access Journals (Sweden)

    B. Błaszczak

    2015-06-01

    Full Text Available In poe experiment, it was found that Rhizoctonia solani was most pathogenic to potato sprouts at 14.8 and 17.4°C. At a third temperature applied (9.9°C, the pathologenicity was much lower. The higher temperatures decreased the fungicidal activity of Ceresan Nassbeize and Rizokton. The addition to the soil of 1 and 3% of corn straw did not affect the pathogenicity of the fungus.

  20. Enthalpy measurement of coal-derived liquids. Technical progress report, August-January 1982. [Isobars of 517. 1, 689. 5, 1034. 2, 1379. 1, and 10342. 5 kPa temperature range of 340 to 664/sup 0/K

    Energy Technology Data Exchange (ETDEWEB)

    Kidnay, A.J.; Yesavage, V.F.

    1982-04-01

    The compound quinoline is discussed. Process flow in the flow calorimeter, operational problems, and equipment modifications are described. Procedural modifications, including a new sample purification procedure, are described. Quinoline enthalpy data are presented along the isobars of 517.1, 689.5, 1034.2, 1379.0, 3799.1, and 10342.5 kPa over a temperature range of 340 to 664/sup 0/K. Experimental enthalpy values and thermodynamic properties derived from this data are compared to corresponding values found in the literature, and to values predicted using computer aided calculations involving three correlations. The three correlations are: the SRK equation of state, and two modifications of the BWR equation of state by Kesler et al. and Starling, respectively. In general, the correlations do not accurately predict the thermodynamic behavior of quinoline. However, the experimental data compare well with available literature data for quinoline vapor pressures.

  1. Investigation of reactivity and structure formation in a K-Te-U oxo-system under high-temperature/high-pressure conditions.

    Science.gov (United States)

    Xiao, Bin; Kegler, Philip; Bosbach, Dirk; Alekseev, Evgeny V

    2016-09-27

    The high-temperature/high-pressure treatment of the K-Te-U oxo-family at 1100 °C and 3.5 GPa results in the crystallization of a series of novel uranyl tellurium compounds, K2[(UO2)3(TeIVO3)4], K2[(UO2)TeO14], α-K2[(UO2)TeVIO5] and β-K2[(UO2)TeVIO5]. In contrast to most of the reported uranyl compounds which are favorable in layered structures, we found that under extreme conditions, the potassium uranyl oxo-tellurium compounds preferably crystallized in three-dimensional (3D) framework structures with complex topologies. Anion topology analysis indicates that the 3D uranyl tellurite anionic framework observed in K2[(UO2)3(TeIVO3)4] is attributable to the additional linkages of TeO3 polyhedra connecting with TeO4 disphenoids from the neighboring U-Te layers. The structure of K2[(UO2)TeO14] can be described based on [UTe6O26]22- clusters, where six TeO5 polyhedra enclose a hexagonal cavity in which a UO8 polyhedron is located. The [UTe6O26]22- clusters are further linked by TeO5 square pyramids to form the 3D network. Similar to uranyl tellurates, both α-K2[(UO2)TeVIO5] and β-K2[(UO2)TeVIO5] contain TeO6 octahedra which share a common face to form a dimeric Te2O10 unit. However, in α-K2[(UO2)TeVIO5], these Te2O10 units connect with UO6 tetragonal bipyramids to form a 3D structural framework, while in β-K2[(UO2)TeVIO5], the same Te2O10 dimers are observed to link with UO7 pentagonal bipyramids, forming 2D layers. Raman measurements were carried out and the vibration bands related to TeIV-O, TeVI-O and UVI-O bonds are discussed.

  2. Reaction between B{sub 4}C and austenitic stainless steel in oxidizing atmosphere at temperatures below 1673 K

    Energy Technology Data Exchange (ETDEWEB)

    Sasaki, Ryosuke; Ueda, Shigeru, E-mail: tie@tagen.tohokku.ac.jp; Kim, Sun-Joong; Gao, Xu; Kitamura, Shin-ya

    2015-11-15

    Synopsis: The control rod of a light water nuclear reactor is constructed of a pole comprising stainless steel filled with a boron carbide (B{sub 4}C) core. To appraise the stability of this control rod in the event of a severe accident, the reactions of the system of B{sub 4}C and grade 304 austenitic stainless steel (SS) were observed at 1473 K in Ar, air, and a mixture of both. To clarify the reaction mechanism and the influence of the oxygen partial pressure, the weight change ratio was monitored and differential thermal analysis was performed at the temperature range from room temperature to 1673 K to monitor the reaction under controlled oxygen partial pressure. The results showed that there was no direct reaction between B{sub 4}C and SS. When the temperature was higher than the melting point of B{sub 2}O{sub 3} (743 K), the molten B{sub 2}O{sub 3} formed by oxidation of B{sub 4}C covered the surface of SS by spreading wetting. This B{sub 2}O{sub 3} layer functioned to transport oxygen from the atmosphere to SS, leading to accelerated oxidation of SS. As a result, a Fe–Cr–Ni–B–O oxide phase covered the surface of SS. Oxygen continuously entered the oxide phase with prolonged reaction time, and oxides such as Fe{sub 2}O{sub 3}, Fe{sub 3}O{sub 4}, and FeOx–Cr{sub 2}O{sub 3} were found on the outer layer. Therefore, in the presence of B{sub 2}O{sub 3} formed by oxidation of B{sub 4}C, the oxidation of SS was accelerated below the eutectic temperature of the Fe–C system. - Highlights: • The reactions of the system of B{sub 4}C and grade 304 austenitic stainless steel (SS) were studied at 1473 K. • The molten B{sub 2}O{sub 3} formed by oxidation of B{sub 4}C covered the surface of SS by spreading wetting at the temperature above 743 K. • In the presence of B{sub 2}O{sub 3}, the oxidation of SS was accelerated.

  3. Quasiclassical Trajectory Calculations of the Rate Constant of the OH + HBr → Br + H2O Reaction Using a Full-Dimensional Ab Initio Potential Energy Surface Over the Temperature Range 5 to 500 K.

    Science.gov (United States)

    de Oliveira-Filho, Antonio G S; Ornellas, Fernando R; Bowman, Joel M

    2014-02-20

    We report a permutationally invariant, ab initio potential energy surface (PES) for the OH + HBr → Br + H2O reaction. The PES is a fit to roughly 26 000 spin-free UCCSD(T)/cc-pVDZ-F12a energies and has no classical barrier to reaction. It is used in quasiclassical trajectory calculations with a focus on the thermal rate constant, k(T), over the temperature range 5 to 500 K. Comparisons with available experimental data over the temperature range 23 to 416 K are made using three approaches to treat the OH rotational and associated electronic partition function. All display an inverse temperature dependence of k(T) below roughly 160 K and a nearly constant temperature dependence above 160 K, in agreement with experiment. The calculated rate constant with no treatment of spin-orbit coupling is overall in the best agreement with experiment, being (probably fortuitously) within 20% of it.

  4. Temperature- and pH-induced structural changes in the membrane of the hyperthermophilic archaeon Aeropyrum pernix K1.

    Science.gov (United States)

    Ulrih, Natasa Poklar; Adamlje, Urska; Nemec, Marjanca; Sentjurc, Marjeta

    2007-10-01

    The influence of pH and temperature on the structural organization, fluidity and permeability of the hyperthermophilic archaeon membrane was investigated in situ by a combination of electron paramagnetic resonance (EPR) and fluorescence emission spectroscopy. For EPR measurements, Aeropyrum pernix cells, after growing at different pHs, were spin-labeled with the doxyl derivative of palmitic acid methylester (MeFASL(10,3)). From the EPR spectra maximal hyperfine splitting (2A (max)) and empirical correlation time (tau (emp)), which are related to mean membrane fluidity, were determined. The mean membrane fluidity increases with temperature and depends on the pH of the growth medium. Computer simulation of the EPR spectra shows that membrane of A. pernix is heterogeneous and consists of the regions characterized with three different types of motional characteristics, which define three types of membrane domains. Order parameter and proportion of the spin probes in the three types of domains define mean membrane fluidity. The fluidity changes of the membrane with pH and temperature correlate well with the ratio between the fluorescence emission intensity of the first and third bands in the vibronic spectra of pyrene, I(1)/I(3). At pH 7.0 a decrease of I(1)/I(3) from 2.0 to 1.2, due to the penetration of pyrene into the nonpolar membrane region, is achieved at temperatures above 65 degrees C, the lower temperature limit of A. pernix growth.

  5. Resonance Stabilization Effects on Ketone Autoxidation: Isomer-Specific Cyclic Ether and Ketohydroperoxide Formation in the Low-Temperature (400-625 K) Oxidation of Diethyl Ketone.

    Science.gov (United States)

    Scheer, Adam M; Eskola, Arkke J; Osborn, David L; Sheps, Leonid; Taatjes, Craig A

    2016-11-03

    The pulsed photolytic chlorine-initiated oxidation of diethyl ketone [DEK; (CH3CH2)2C═O], 2,2,4,4-d4-DEK [d4-DEK; (CH3CD2)2C═O], and 1,1,1,5,5,5-d6-DEK [d6-DEK; (CD3CH2)2C═O] is studied at 8 torr and 1-2 atm and from 400-625 K. Cl atoms produced by laser photolysis react with diethyl ketone to form either primary (3-pentan-on-1-yl, RP) or secondary (3-pentan-on-2-yl, RS) radicals, which in turn react with O2. Multiplexed time-of-flight mass spectrometry, coupled to either a hydrogen discharge lamp or tunable synchrotron photoionizing radiation, is used to detect products as a function of mass, time, and photon energy. At 8 torr, the nature of the chain propagating cyclic ether + OH channel changes as a function of temperature. At 450 K, the production of OH is mainly in conjunction with formation of 2,4-dimethyloxetan-3-one, resulting from reaction of the resonance-stabilized secondary RS with O2. In contrast, at 550 K and 8 torr, 2-methyl-tetrahydrofuran-3-one, originating from oxidation of the primary radical (RP), is observed as the dominant cyclic ether product. Formation of both of these cyclic ether production channels proceeds via a resonance-stabilized hydroperoxy alkyl (QOOH) intermediate. Little or no ketohydroperoxide (KHP) is observed under the low-pressure conditions. At higher O2 concentrations and higher pressures (1-2 atm), a strong KHP signal appears as the temperature is increased above 450 K. Definitive isomeric identification from measurements on the deuterated DEK isotopologues indicates the favored pathway produces a γ-KHP via resonance-stabilized alkyl, QOOH, and HOOPOOH radicals. Time-resolved measurements reveal the KHP formation becomes faster and signal more intense upon increasing temperature from 450 to 575 K before intensity drops significantly at 625 K. The KHP time profile also shows a peak followed by a gradual depletion for the extent of experiment. Several tertiary products exhibit a slow accumulation in coincidence with

  6. Development and testing of a 2.5 kW synchronous generator with a high temperature superconducting stator and permanent magnet rotor

    Science.gov (United States)

    Qu, Timing; Song, Peng; Yu, Xiaoyu; Gu, Chen; Li, Longnian; Li, Xiaohang; Wang, Dewen; Hu, Boping; Chen, Duxing; Zeng, Pan; Han, Zhenghe

    2014-04-01

    High temperature superconducting (HTS) armature windings have the potential for increasing the electric loading of a synchronous generator due to their high current transport capacity, which could increase the power density of an HTS rotating machine. In this work, a novel synchronous generator prototype with an HTS stator and permanent magnet rotor has been developed. It has a basic structure of four poles and six slots. The armature winding was constructed from six double-pancake race-track coils with 44 turns each. It was designed to deliver 2.5 kW at 300 rpm. A concentrated winding configuration was proposed, to prevent interference at the ends of adjacent HTS coils. The HTS stator was pressure mounted into a hollow Dewar cooled with liquid nitrogen. The whole stator could be cooled down to around 82 K by conduction cooling. In the preliminary testing, the machine worked properly and could deliver 1.8 kW power when the armature current was 14.4 A. Ic for the HTS coils was found to be suppressed due to the influence of the temperature and the leakage field.

  7. Measurements of complex permittivity of microwave substrates in the 20 to 300 K temperature range from 26.5 to 40.0 GHz

    Science.gov (United States)

    Miranda, Felix A.; Gordon, William L.; Heinen, Vernon O.; Ebihara, Ben T.; Bhasin, Kul B.

    1990-01-01

    A knowledge of the dielectric properties of microwve substrates at low temperatures is useful in the design of superconducting microwave circuits. Results are reported for a study of the complex permittivity of sapphire (Al2O3), magnesium oxide (MgO), silicon oxide (SiO2), lanthanum aluminate (LaAlO3), and zirconium oxide (ZrO2), in the 20 to 300 Kelvin temperature range, at frequencies from 26.5 to 40.0 GHz. The values of the real and imaginary parts of the complex permittivity were obtained from the scattering parameters, which were measured using an HP-8510 automatic network analyzer. For these measurements, the samples were mounted on the cold head of a helium gas closed cycle refrigerator, in a specially designated vacuum chamber. An arrangement of wave guides, with mica windows, was used to connect the cooling system to the network analyzer. A decrease in the value of the real part of the complex permittivity of these substrates, with decreasing temperature, was observed. For MgO and Al2O3, the decrease from room temperature to 20 K was of 7 and 15 percent, respectively. For LaAlO3, it decreased by 14 percent, for ZrO2 by 15 percent, and for SiO2 by 2 percent, in the above mentioned temperature range.

  8. (Liquid + liquid) equilibria for mixtures of (ethylene glycol + benzene + cyclohexane) at temperatures (298.15, 308.15, and 318.15) K

    Energy Technology Data Exchange (ETDEWEB)

    Mohammad Reza Seyedein Ghannad, S. [School of Chemical, Gas and Petroleum Engineering, Semnan University, Semnan 35195-363 (Iran, Islamic Republic of); Lotfollahi, Mohammad Nader, E-mail: mnlotfollahi@semnan.ac.i [School of Chemical, Gas and Petroleum Engineering, Semnan University, Semnan 35195-363 (Iran, Islamic Republic of); Asl, Ali Haghighi [School of Chemical, Gas and Petroleum Engineering, Semnan University, Semnan 35195-363 (Iran, Islamic Republic of)

    2011-03-15

    Experimental (liquid + liquid) equilibrium (LLE) data for a ternary system containing (ethylene glycol + benzene + cyclohexane) were determined at temperatures (298.15, 308.15, and 318.15) K and at atmospheric pressure. The experimental distribution coefficients and selectivity factors are presented to evaluate the efficiency of the solvent for extraction of benzene from cyclohexane. The effect of temperature in extraction of benzene from the (benzene + cyclohexane) mixture indicated that at lower temperatures the selectivity (S) is higher, but the distribution coefficient (K) is rather lower. The LLE results for the system studied were used to obtain binary interaction parameters in the UNIQUAC and NRTL models by minimizing the root mean square deviations (RMSD) between the experimental results and calculated results. Using the interaction parameters obtained, the phase equilibria in the systems were calculated and plotted. The NRTL model fits the (liquid + liquid) equilibrium data of the mixture studied slightly better. The root mean square deviations (RMSDs) obtained comparing calculated and experimental two-phase compositions are 0.92% for the NRTL model and 0.95% for the UNIQUAC model.

  9. Isothermal vapour–liquid equilibria in cyclohexanone + dichloroalkane binary mixtures at temperatures from 298.15 to 318.15 K

    Directory of Open Access Journals (Sweden)

    DANA DRAGOESCU

    2011-02-01

    Full Text Available The vapour pressures of binary mixtures of cyclohexanone + dichloroalkane (1,3-dichloropropane and 1,4-dichlorobutane were measured at temperatures between 298.15 and 318.15 K. The vapour pressures vs. liquid phase composition data were used to calculate the activity coefficients of the two components and the excess molar Gibbs energies GE for the mixtures, using the Barker method and the Redlich–Kister, Wilson, NRTL and UNIQUAC equations, taking into account the vapour phase imperfection in terms of the 2nd virial coefficient. No significant difference between the GE values obtained with these equations was observed.

  10. A facility for X-ray diffraction in magnetic fields up to 25 T and temperatures between 15 and 295 K

    Energy Technology Data Exchange (ETDEWEB)

    Wang, S.; Kovalev, A. E., E-mail: kovalev@magnet.fsu.edu; Suslov, A. V. [National High Magnetic Field Laboratory, Tallahassee, Florida 32310 (United States); Siegrist, T. [National High Magnetic Field Laboratory, Tallahassee, Florida 32310 (United States); Department of Chemical & Biomedical Engineering, FAMU-FSU College of Engineering, Tallahassee, Florida 32310 (United States)

    2015-12-15

    A facility for X-ray diffraction has been developed at the National High Magnetic Field Laboratory. It brings diffraction capability to the 25 T Florida split coil magnet and implements temperature control in a range of 15–295 K using a cold finger helium cryostat. This instrument represents an alternative to pulsed magnetic field systems, and it exceeds the static magnetic fields currently available at synchrotron facilities. Magnetic field compatibility of an X-ray source and detectors with the sizable magnetic fringe fields emanating from the magnet constrained the design of the diffractometer.

  11. 50-kHz-rate 2D imaging of temperature and H2O concentration at the exhaust plane of a J85 engine using hyperspectral tomography.

    Science.gov (United States)

    Ma, Lin; Li, Xuesong; Sanders, Scott T; Caswell, Andrew W; Roy, Sukesh; Plemmons, David H; Gord, James R

    2013-01-14

    This paper describes a novel laser diagnostic and its demonstration in a practical aero-propulsion engine (General Electric J85). The diagnostic technique, named hyperspectral tomography (HT), enables simultaneous 2-dimensional (2D) imaging of temperature and water-vapor concentration at 225 spatial grid points with a temporal response up to 50 kHz. To our knowledge, this is the first time that such sensing capabilities have been reported. This paper introduces the principles of the HT techniques, reports its operation and application in a J85 engine, and discusses its perspective for the study of high-speed reactive flows.

  12. Low Temperature (30 K) TID Test Results of a Radiation Hardened 128 Channel Serial-to-Parallel Converter

    Science.gov (United States)

    Meyer, Stephen; Buchner, Stephen; Moseley, Harvey; Ray, Knute; Tuttle, Jim; Quinn, Ed; Buchanan, Ernie; Bloom, Dave; Hait, Tom; Pearce, Mike; hide

    2006-01-01

    This viewgraph presentation reviews the low temperature, Total Ionizing Dose (TID) tests of radiation hardened serial to parallel converter to be used on the James Webb Space Telescope. The test results show that the original HV583 level shifter - a COTS part -was not suitable for JWST because the supply currents exceeded specs after 20 krad( Si) .The HV584 - functionally similar to the HV583 -was designed using RHBD approach that reduced the leakage currents to within acceptable levels and had only a small effect on the level-shifted output voltage.

  13. Temperature dependence of the thermal diffusivity of GaAs in the 100-305 K range measured by the pulsed photothermal displacement technique

    Science.gov (United States)

    Soltanolkotabi, M.; Bennis, G. L.; Gupta, R.

    1999-01-01

    We have measured the variation of the value of the thermal diffusivity of semi-insulating GaAs in the 100-305 K range. The method used is the pulsed photothermal displacement technique. This is a noncontact technique, and the value of the thermal diffusivity is derived from the temporal evolution of the signal rather than its amplitude. This makes the technique less susceptible to uncertainties. We find that the temperature dependence of the thermal conductivity of semi-insulating GaAs follows a power law as T-1.62, in disagreement with results obtained previously. Possible reasons for the deviation within this very important intermediate temperature range are discussed.

  14. Suppression of spikes during posttetanic hyperpolarization in auditory neurons: the role of temperature, I(h) currents, and the Na(+)-K(+)-ATPase pump.

    Science.gov (United States)

    Kim, Jun Hee; von Gersdorff, Henrique

    2012-10-01

    In vivo recordings from postsynaptic neurons in the medial nucleus of the trapezoid body (MNTB), an auditory brain stem nucleus, show that acoustic stimulation produces a burst of spikes followed by a period of hyperpolarization and suppressed spiking activity. The underlying mechanism for this hyperpolarization and reduced spiking is unknown. Furthermore, the mechanisms that control excitability and resting membrane potential are not fully determined for these MNTB neurons. In this study we investigated the excitability of principal neurons from the MNTB after high-frequency afferent fiber stimulation, using whole cell recordings from postnatal day 15-17 rat brain stem slices. We found that Na(+)-K(+)-ATPase activity mediates a progressive hyperpolarization during a prolonged tetanic train and a posttetanic hyperpolarization (PTH) at the end of the train, when postsynaptic action potentials failed to fire. Raising the temperature to more physiological levels (from 22 to 35°C) depolarized the resting membrane potential of both presynaptic and postsynaptic cells and decreased the latency of action potential firing during PTH. Higher temperatures also reduced the presynaptic calyx action potential failure rates by 50% during presynaptic PTH, thus increasing the safety-factor for presynaptic spiking. The effect of temperature on hyperpolarization-activated cation current (I(h)) is reflected in the resting potential at both pre- and postsynaptic neurons. We thus propose that temperature-sensitive Na(+)-K(+)-ATPase activity and I(h) contribute to set the resting membrane potential and produce a brief period of suppressed spiking (or action potential failures) after a prolonged high-frequency afferent tetanus.

  15. Selection of optimal sintering temperature of K0.5Na0.5NbO3 ceramics for electromechanical applications

    Directory of Open Access Journals (Sweden)

    Gaurav Vats

    2014-03-01

    Full Text Available This paper has considered the selection of the optimal processing parameter (sintering temperature leading to best possible properties of K0.5Na0.5NbO3 (KNN for electromechanical applications. Vital piezoelectric properties for such applications include the piezoelectric coupling coefficient (kp, piezoelectric coefficient (d31, Curie temperature (Tc, remanent polarization (Pr, coercive field (Ec, density (ρ, elastic compliance (S11E and S12E and dielectric loss (tan δ. The weights and priority of these physical properties for KNN are calculated using the modified digital logic (MDL method. The priority order of these properties used for the selection of optimal processing parameters is as d31>tan δ>S11E=S12E>Tc=Pr>ρ>kp>Ec. The weights obtained using MDL are further incorporated with analytic hierarchy process (AHP and VlseKriterijumska Optimisacija I Kompromisno Resenje (VIKOR in order to determine the optimal sintering temperature for KNN. Both methods suggest that 1080 °C and 1120 °C are the most and least desirable sintering temperatures, respectively. Finally, sensitivity analysis is performed for the robustness of our results and prediction of most influential parameter in terms of sensitivity. tan δ is found to be the most sensitive property for alteration in the present ranking.

  16. Beamline Electrostatic Levitator (BESL) for in-situ High Energy K-Ray Diffraction Studies of Levitated Solids and Liquids at High Temperature

    Science.gov (United States)

    Gangopadhyay, A. K.; Lee, G. W.; Kelton, K. F.; Rogers, J. R.; Goldman, A. I.; Robinson, D. S.; Rathz, T. J.; Hyers, R. W.

    2005-01-01

    Determinations of the phase formation sequence, the crystal structures and the thermodynamic properties of materials at high temperatures are difficult because of contamination from the sample container and environment. Containerless processing techniques, such as electrostatic (ESL), electromagnetic (EML), aerodynamic, and acoustic levitation, are most suitable these studies. An adaptation of ESL for in-situ structural studies of a wide range of materials, including metals, semiconductors, insulators using high energy (125 keV) synchrotron x-rays is described here. This beamline ESL (BESL) allows the in-situ determination of the atomic structures of equilibrium solid and liquid phases, including undercooled liquids, as well as real-time studies of solid-solid and liquid-solid phase transformations. The use of image plate (MAR345) or GE-Angio detectors enables fast (30 ms - 1s) acquisition of complete diffraction patterns over a wide q-range (4 - 140/mm). The wide temperature range (300 - 2500 K), containerless processing under high vacuum (10(exp -7) - 10(exp -8) torr), and fast data acquisition, make BESL particularly suitable for phase diagram studies of high temperature materials. An additional, critically important, feature of BESL is the ability to also make simultaneous measurement of a host of thermo-physical properties, including the specific heat, enthalpy of transformation, solidus and liquidus temperatures, density, viscosity, and surface tension; all on the same sample and simultaneous with the structural measurements.

  17. Evaluation of high specific-heat ceramic for regenerator use at temperatures between 2-30 K

    Science.gov (United States)

    Lawless, W. N.

    1979-01-01

    Specific heat, thermal conductivity (both in the range 2-30 K), and microhardness data were measured on the ceramics labelled LS-8, LS-8A, and LS-8A doped with CsI, SnCl2, and AgCl. A work hardened sample of LS-8A was also studied in an effort to determine the feasibility of using these types of LS-8 materials to replace Pb spheres in the regenerator of the JPL cryocooler. The LS-8A materials are all more than an order of magnitude harder than Pb, and the dopants do not significantly improve the hardness. However, the SnCl2 dopant has a remarkable effect in improving the specific heat and thermal conductivity of LS-8A. The SnCl2 doping level which maximized the regenerator enthalpy change in going from an unloaded to a loaded condition was found to be 0.2 percent SnCl2 in LS-8A. It was also found that the enthalpy change for a regenerator employing the LS-8A material is more than three times larger than for the Pb spheres case. The use of rods, rather than spheres, of optimally doped LS-8A in regenerators is discussed.

  18. Kinetics of cisplatin binding to short r(GG) containing miRNA mimics - influence of Na(+)versus K(+), temperature and hydrophobicity on reactivity.

    Science.gov (United States)

    Alshiekh, Alak; Clausén, Maria; Elmroth, Sofi K C

    2015-07-28

    Nucleic acids are well recognized targets for platinum-based anticancer drugs, with RNA and DNA being kinetically comparable. In the case of RNA, previous studies have shown that the reaction between small duplex RNAs (dsRNAs) and monoaquated cisplatin (cis-Pt(NH3)2Cl(OH2)(+), ) can be followed by the metal induced hyperchromicity occurring directly after addition of to e.g. microRNA mimics. In the present study, we have used this approach to compare thermal stability and reactivity between intracellularly- and extracellularly relevant salt concentration (CNa(+) and CK(+)ca. 0.1 M), and also as a function of increased hydrophobicity (10% v/v EtOH). In addition, reactivity was studied as a function of temperature in the interval ca. 5-20 °C below the respective dsRNA melting temperatures (Tms). Four different 13- to 20-mer dsRNAs with two different central sequence motifs were used as targets containing either a central r(GG)·r(CC)- or r(GG)·r(UAU)-sequence. The reactions exhibited half-lives in the minute- to hour range at 38 °C in the presence of excess in the μM range. Further, a linear dependence was found between C and the observed pseudo-first-order rate constants. The resulting apparent second-order rate constants were significantly larger for the lower melting r(GG)·r(UAU)-containing sequences compared with that of the fully complementary ones; the higher and lower reactivities represented by RNA-1-3 and RNA-1-1 with k2,appca. 30 and 8 M(-1) s(-1) respectively at CNa(+) = 122 mM. For all RNAs a common small, but significant, trend was observed with increased reactivity in the presence of K(+) compared with Na(+), and decreased reactivity in the presence of EtOH. Finally, the temperature dependence of k2,app was evaluated using the Eyring equation. The retrieved activation parameters reveal positive values for both ΔH(≠) and ΔS(≠) for all dsRNAs, in the range ca. 23-34 kcal mol(-1) and 22-57 cal K(-1) mol(-1) respectively. These values indicate

  19. Linear chains of magnetic ions stacked with variable distance: ferromagnetic ordering with a Curie temperature above 20 K

    Energy Technology Data Exchange (ETDEWEB)

    Friedlaender, Stefan; Poeppl, Andreas [Abteilung Magnetische Resonanz komplexer Quantenfestkoerper, Fakultaet fuer Physik und Geowissenschaften, Universitaet Leipzig (Germany); Liu, Jinxuan [Institute of Artificial Photosynthesis, State Key Laboratory of Fine Chemicals, Dalian University of Technology (China); Addicoat, Matt; Petkov, Petko; Vankova, Nina; Rueger, Robert; Kuc, Agnieszka [Wilhelm-Ostwald-Institut fuer Physikalische und Theoretische Chemie, Leipzig (Germany); Guo, Wei; Zhou, Wencai; Wang, Zhengbang; Weidler, Peter G.; Woell, Christof [Institut fuer Funktionelle Grenzflaechen, Karlsruher Institut fuer Technologie, Hermann-von-Helmholtz-Platz 1, 76344, Eggenstein-Leopoldshafen (Germany); Lukose, Binit [Engineering and Science, Department of Physics and Earth Science, Jacobs University Bremen (Germany); Ziese, Michael [Abteilung Supraleitung und Magnetismus, Fakultaet fuer Physik und Geowissenschaften, Universitaet Leipzig (Germany); Heine, Thomas [Engineering and Science, Department of Physics and Earth Science, Jacobs University Bremen (Germany); Wilhelm-Ostwald-Institut fuer Physikalische und Theoretische Chemie, Leipzig (Germany)

    2016-10-04

    We have studied the magnetic properties of the SURMOF-2 series of metal-organic frameworks (MOFs). Contrary to bulk MOF-2 crystals, where Cu{sup 2+} ions form paddlewheels and are antiferromagnetically coupled, in this case the Cu{sup 2+} ions are connected via carboxylate groups in a zipper-like fashion. This unusual coupling of the spin {sup 1}/{sub 2} ions within the resulting one-dimensional chains is found to stabilize a low-temperature, ferromagnetic (FM) phase. In contrast to other ordered 1D systems, no strong magnetic fields are needed to induce the ferromagnetism. The magnetic coupling constants describing the interaction between the individual metal ions have been determined in SQUID experiments. They are fully consistent with the results of ab initio DFT electronic structure calculations. The theoretical results allow the unusual magnetic behavior of this exotic, yet easy-to-fabricate, material to be described in a detailed fashion. (copyright 2016 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  20. Rate constant and mechanism of the reaction Cl + CFCl₂H → CFCl₂ + HCl over the temperature range 298-670 K in N₂ or N₂/O₂ diluent.

    Science.gov (United States)

    Kaiser, E W; Jawad, Khadija M

    2014-05-08

    The rate constant of the reaction Cl + CFCl2H (k1) has been measured relative to the established rate constant for the reaction Cl + CH4 (k2) at 760 Torr. The measurements were carried out in Pyrex reactors using a mixture of CFCl2H, CH4, and Cl2 in either N2 or N2/O2 diluent. Reactants and products were quantified by GC/FID analysis. Cl atoms were generated by irradiation of the mixture with 360 nm light to dissociate the Cl2 for temperatures up to ~550 K. At higher temperature, the Cl2 dissociated thermally, and no irradiation was used. Over the temperature range 298-670 K, k1 is consistently a factor of ~5 smaller than that of k2 with a nearly identical temperature dependence. The optimum non-Arrhenius rate constant is represented by the expression k1 = 1.14 × 10(-22) T(3.49) e(-241/T) cm(3) molecule(-1) s(-1) with an estimated uncertainty of ±15% including uncertainty in the reference reaction. CFCl3 formed from the reaction CFCl2 + Cl2 (k3) is the sole product in N2 diluent. In ~20% O2 at 298 K, the CFCl3 product is suppressed. The rate constant of reaction 3 was measured relative to that of reaction 4 [CFCl2 + O2 (k4)] giving the result k3/k4 = 0.0031 ± 0.0005 at 298 K. An earlier experiment by others observed C(O)FCl to be the major product of reaction channel 4 [formed via the sequence, CFCl2(O2) → CFCl2O → C(O)FCl + Cl]. Our current experiments verified that there is a Cl atom chain reaction in the presence of O2 as required by this mechanism.

  1. A study of the effects of rare-earth elements on the microstructural evolution and deformation behavior of magnesium alloys at temperatures up to 523K

    Science.gov (United States)

    Chakkedath, Ajith

    Due to their high specific strength, lightweight magnesium (Mg) alloys are being increasingly used for applications, such as the automotive industry, where weight savings are critical. In order to develop new alloys and processing methods to achieve higher strength and better formability to compete with currently used metal alloys, it is important to understand the effects of alloying elements, processing, and temperature on the microstructure, mechanical properties, and the deformation behavior. In this dissertation, a systematic investigation on the effects of Nd additions (0-1wt.%) and temperature (298-523K) on the microstructure and the activity of different deformation modes in as-cast and cast-then-extruded Mg-1Mn (wt.%) alloys were performed. For this study, an in-situ testing technique which combines tension and compression testing inside a scanning electron microscope (SEM) with electron backscatter diffraction (EBSD) analysis was employed. The main findings of this work were that the microstructure, strength, and the distribution of the deformation modes varied significantly as a function of Nd content, temperature, and processing. An increase in the Nd content resulted in a weaker texture after extrusion in Mg-1Mn alloys. A combination of slip and twinning mechanisms controlled the tensile deformation in the extruded alloys at ambient temperatures. With an increase in temperature, the twinning activity decreased, and slip mechanisms dominated the deformation. In the extruded Nd-containing alloys, basal slip dominated the deformation, especially at elevated temperatures, suggesting that Nd additions strengthen basal slip. This resulted in excellent elevated-temperature strength retention in extruded Mg-1Mn-1Nd alloy, and a decrease in the Nd content to 0-0.3wt.% resulted in a decrease in the tensile strength at elevated temperatures. In extruded Mg-1Mn, contraction twinning dominated the tensile deformation and this alloy exhibited a lower elongation

  2. Correlations for determining thermodynamic properties of hydrogen-helium gas mixtures at temperatures from 7,000 to 35,000 K

    Science.gov (United States)

    Zoby, E. V.; Gnoffo, P. A.; Graves, R. A., Jr.

    1976-01-01

    Simple relations for determining the enthalpy and temperature of hydrogen-helium gas mixtures were developed for hydrogen volumetric compositions from 1.0 to 0.7. These relations are expressed as a function of pressure and density and are valid for a range of temperatures from 7,000 to 35,000 K and pressures from 0.10 to 3.14 MPa. The proportionality constant and exponents in the correlation equations were determined for each gas composition by applying a linear least squares curve fit to a large number of thermodynamic calculations obtained from a detailed computer code. Although these simple relations yielded thermodynamic properties suitable for many engineering applications, their accuracy was improved significantly by evaluating the proportionality constants at postshock conditions and correlating these values as a function of the gas composition and the product of freestream velocity and shock angle. The resulting equations for the proportionality constants in terms of velocity and gas composition and the corresponding simple realtions for enthalpy and temperature were incorporated into a flow field computational scheme. Comparison was good between the thermodynamic properties determined from these relations and those obtained by using a detailed computer code to determine the properties. Thus, an appreciable savings in computer time was realized with no significant loss in accuracy.

  3. An investigation into the effect of spray drying temperature and atomizing conditions on miscibility, physical stability, and performance of naproxen-PVP K 25 solid dispersions.

    Science.gov (United States)

    Paudel, Amrit; Loyson, Yves; Van den Mooter, Guy

    2013-04-01

    The present study investigates the effect of changing spray drying temperature (40°C-120°C) and/or atomizing airflow rate (AR; 5-15 L/min) on the phase structure, physical stability, and performance of spray-dried naproxen-polyvinylpyrrolidone (PVP) K 25 amorphous solid dispersions. The modulated differential scanning calorimetry, attenuated total internal reflectance-Fourier transform infrared, and powder X-ray diffractometry (pXRD) studies revealed that higher inlet temperature (IT) or atomization airflow leads to the formation of amorphous-phase-separated dispersions with higher strongly H-bonded and free PVP fractions, whereas that prepared with the lowest IT was more homogeneous. The dispersion prepared with the lowest atomization AR showed trace crystallinity. Upon exposure to 75% relative humidity (RH) for 3 weeks, the phase-separated dispersions generated by spray drying at higher temperature or higher atomization airflow retained relatively higher amorphous drug fraction compared with those prepared at slow evaporation conditions. The humidity-controlled pXRD analysis at 98% RH showed that the dispersion prepared with highest atomization AR displayed the slowest kinetics of recrystallization. The molecular-level changes occurring during recrystallization at 98% RH was elucidated by spectroscopic monitoring at the same humidity. The rate and extent of the drug dissolution was the highest for dispersions prepared at the highest atomizing AR and the lowest for that prepared with the slowest atomizing condition. Copyright © 2013 Wiley Periodicals, Inc.

  4. Time-resolved measurements of product formation in the low-temperature (550-675 K) oxidation of neopentane: a probe to investigate chain-branching mechanism.

    Science.gov (United States)

    Eskola, Arkke J; Antonov, Ivan O; Sheps, Leonid; Savee, John D; Osborn, David L; Taatjes, Craig A

    2017-05-31

    Product formation, in particular ketohydroperoxide formation and decomposition, were investigated in time-resolved, Cl-atom initiated neopentane oxidation experiments in the temperature range 550-675 K using a photoionization time-of-flight mass spectrometer. Ionization light was provided either by Advanced Light Source tunable synchrotron radiation or ∼10.2 eV fixed energy radiation from a H2-discharge lamp. Experiments were performed both at 1-2 atm pressure using a high-pressure reactor and also at ∼9 Torr pressure employing a low-pressure reactor for comparison. Because of the highly symmetric structure of neopentane, ketohydroperoxide signal can be attributed to a 3-hydroperoxy-2,2-dimethylpropanal isomer, i.e. from a γ-ketohydroperoxide (γ-KHP). The photoionization spectra of the γ-KHP measured at low- and high pressures and varying oxygen concentrations agree well with each other, further supporting they originate from the single isomer. Measurements performed in this work also suggest that the "Korcek" mechanism may play an important role in the decomposition of 3-hydroperoxy-2,2-dimethylpropanal, especially at lower temperatures. However, at higher temperatures where γ-KHP decomposition to hydroxyl radical and oxy-radical dominates, oxidation of the oxy-radical yields a new important channel leading to acetone, carbon monoxide, and OH radical. Starting from the initial neopentyl + O2 reaction, this channel releases altogether three OH radicals. A strongly temperature-dependent reaction product is observed at m/z = 100, likely attributable to 2,2-dimethylpropanedial.

  5. Temperature-jump apparatus with Raman detection based on a solid-state tunable (1.80-2.05 microm) kHz optical parametric oscillator laser.

    Science.gov (United States)

    Balakrishnan, Gurusamy; Hu, Ying; Spiro, Thomas G

    2006-04-01

    The operating characteristics of a pulsed (10 ns) tunable near-infrared (NIR) laser source are described for temperature-jump (T-jump) applications. A Q-switched Nd:YLF laser (approximately 10 ns pulses) with a 1 kHz repetition rate is used to pump a potassium titanyl arsenate (KTA) crystal-based optical parametric oscillator (OPO), producing approximately 1 mJ NIR pulses that are tunable (1.80-2.05 microm) across the 1.9 microm vibrational overtone band of water. This T-jump source has been coupled to a deep ultraviolet (UV) probe laser for Raman studies of protein dynamics. T-jumps of up to 30 degrees C, as measured via the O-H stretching Raman band of water, are readily achieved. Application to cytochrome c unfolding is demonstrated.

  6. A Data-Model Comparison over Europe using a new 2000-yr Summer Temperature Reconstruction from the PAGES 2k Regional Network and Last-Millennium GCM Simulations

    Science.gov (United States)

    Smerdon, Jason; Werner, Johannes; Fernandez-Donado, Laura; Buntgen, Ulf; Charpentier Ljungqvist, Fredrik; Esper, Jan; Fidel Gonzalez-Rouco, J.; Luterbacher, Juerg; McCarroll, Danny; Wagner, Sebastian; Wahl, Eugene; Wanner, Heinz; Zorita, Eduardo

    2013-04-01

    A new reconstruction of European summer (JJA) land temperatures is presented and compared to 37 forced transient simulations of the last millennium from coupled General Circulation Models (CGCMs). The reconstructions are derived from eleven annually resolved tree-ring and documentary records from ten European countries/regions, compiled as part of the Euro_Med working group contribution to the PAGES 2k Regional Network. Records were selected based upon their summer temperature signal, annual resolution, and time-continuous sampling. All tree-ring data were detrended using the Regional Curve Standardization (RCS) method to retain low-frequency variance in the resulting mean chronologies. A nested Composite-Plus-Scale (CPS) mean temperature reconstruction extending from 138 B.C.E. to 2003 C.E. was derived using nine nests reflecting the availability of predictors back in time. Each nest was calculated using a weighted composite based on the correlation of each proxy with the CRUTEM4v mean European JJA land temperature (35°-70°N, 10°W-40°E). The CPS methodology was implemented using a sliding calibration period, initially extending from 1850-1953 C.E. and incrementing by one year until reaching the final period of 1900-2003 C.E. Within each calibration step, the 50 years excluded from calibration were used for validation. Validation statistics across all reconstruction ensemble members within each nest indicate skillful reconstructions (RE: 0.42-0.64; CE: 0.26-0.54) and are all above the maximum validation statistics achieved in an ensemble of red noise benchmarking experiments. A gridded (5°x5°) European summer (JJA) temperature reconstruction back to 750 C.E. was derived using Bayesian inference together with a localized stochastic description of the underlying processes. Instrumental data are JJA means from the 5° European land grid cells in the CRUTEM4v dataset. Predictive experiments using the full proxy data were made, resulting in a multivariate

  7. Technical Note: VUV photodesorption rates from water ice in the 120–150 K temperature range – significance for Noctilucent Clouds

    Directory of Open Access Journals (Sweden)

    M. Yu. Kulikov

    2011-02-01

    Full Text Available Laboratory studies have been carried out with the aim to improve our understanding of physicochemical processes which take place at the water ice/air interface initiated by solar irradiation with a wavelength of 121.6 nm. It was intended to mimic the processes of ice particles characteristic of Noctilucent Clouds (NLCs. The experimental set-up used includes a high-vacuum chamber, a gas handling system, a cryostat with temperature controller, an FTIR spectrometer, a vacuum ultraviolet hydrogen lamp, and a microwave generator. We report the first results of measurements of the absolute photodesorption rate (loss of substance due to the escape of photoproducts into gas phase from thin (20–100 nm water ice samples kept in the temperature range of 120–150 K. The obtained results show that a flow of photoproducts into the gas phase is considerably lower than presumed in the recent study by Murray and Plane (2005. The experiments indicate that almost all photoproducts remain in the solid phase, and the principal chemical reaction between them is the recombination reaction H + OH → H2O which is evidently very fast. This means that direct photolysis of mesospheric ice particles seems to have no significant impact on the gas phase chemistry of the upper mesosphere.

  8. A ∼32–70 K FORMATION TEMPERATURE RANGE FOR THE ICE GRAINS AGGLOMERATED BY COMET 67 P/CHURYUMOV–GERASIMENKO

    Energy Technology Data Exchange (ETDEWEB)

    Lectez, S.; Simon, J.-M.; Salazar, J. M. [Laboratoire Interdisciplinaire Carnot de Bourgogne, UMR 6303, CNRS-Université de Bourgogne Franche Comté, Dijon (France); Mousis, O. [Aix Marseille Université, CNRS, Laboratoire d’Astrophysique de Marseille (LAM), UMR 7326, F-13388 Marseille (France); Picaud, S. [Institut UTINAM, UMR 6213, CNRS-Université de Bourgogne Franche Comté, Besançon (France); Altwegg, K.; Rubin, M., E-mail: jmsimon@u-bourgogne.fr [Physikalisches Institut, University of Bern, Sidlerstrasse 5, CH-3012 Bern (Switzerland)

    2015-05-20

    Grand Canonical Monte Carlo simulations are used to reproduce the N{sub 2}/CO ratio ranging between 1.7 × 10{sup −3} and 1.6 × 10{sup −2} observed in situ in the Jupiter-family comet 67 P/Churyumov–Gerasimenko (67 P) by the ROSINA mass spectrometer on board the Rosetta spacecraft. By assuming that this body has been agglomerated from clathrates in the protosolar nebula (PSN), simulations are developed using elaborated interatomic potentials for investigating the temperature dependence of the trapping within a multiple-guest clathrate formed from a gas mixture of CO and N{sub 2} in proportions corresponding to those expected for the PSN. By assuming that 67 P agglomerated from clathrates, our calculations suggest the cometary grains must have been formed at temperatures ranging between ∼31.8 and 69.9 K in the PSN to match the N{sub 2}/CO ratio measured by the ROSINA mass spectrometer. The presence of clathrates in Jupiter-family comets could then explain the potential N{sub 2} depletion (factor of up to ∼87 compared to the protosolar value) measured in 67 P.

  9. Improved functional expression of recombinant human ether-a-go-go (hERG K+ channels by cultivation at reduced temperature

    Directory of Open Access Journals (Sweden)

    Hamilton Bruce

    2007-12-01

    Full Text Available Abstract Background HERG potassium channel blockade is the major cause for drug-induced long QT syndrome, which sometimes cause cardiac disrhythmias and sudden death. There is a strong interest in the pharmaceutical industry to develop high quality medium to high-throughput assays for detecting compounds with potential cardiac liability at the earliest stages of drug development. Cultivation of cells at lower temperature has been used to improve the folding and membrane localization of trafficking defective hERG mutant proteins. The objective of this study was to investigate the effect of lower temperature maintenance on wild type hERG expression and assay performance. Results Wild type hERG was stably expressed in CHO-K1 cells, with the majority of channel protein being located in the cytoplasm, but relatively little on the cell surface. Expression at both locations was increased several-fold by cultivation at lower growth temperatures. Intracellular hERG protein levels were highest at 27°C and this correlated with maximal 3H-dofetilide binding activity. In contrast, the expression of functionally active cell surface-associated hERG measured by patch clamp electrophysiology was optimal at 30°C. The majority of the cytoplasmic hERG protein was associated with the membranes of cytoplasmic vesicles, which markedly increased in quantity and size at lower temperatures or in the presence of the Ca2+-ATPase inhibitor, thapsigargin. Incubation with the endocytic trafficking blocker, nocodazole, led to an increase in hERG activity at 37°C, but not at 30°C. Conclusion Our results are consistent with the concept that maintenance of cells at reduced temperature can be used to boost the functional expression of difficult-to-express membrane proteins and improve the quality of assays for medium to high-throughput compound screening. In addition, these results shed some light on the trafficking of hERG protein under these growth conditions.

  10. Influence of Design and Process Parameters of 32-nm Advanced-Process High- k p-MOSFETs on Negative-Bias Temperature Instability and Study of Defects

    Science.gov (United States)

    Alimin, A. F. Muhammad; Radzi, A. A. Mohd; Sazali, N. A. F.; Hatta, S. F. Wan Muhamad; Soin, N.; Hussin, H.

    2017-10-01

    Negative-bias temperature instability (NBTI) has become a prominent factor limiting scaling of complementary metal-oxide-semiconductor technology. This work presents a comprehensive simulation study on the effects of critical design parameters of 32-nm advanced-process high- k p-channel metal-oxide-semiconductor field-effect transistors on NBTI. The NBTI mechanism and defects were explored for various geometric and process design parameters over a wide range of values. The NBTI simulation method applied in this work follows the on-the-fly method to capture the mechanisms of fast and slow traps. This work illustrates the dependence of the threshold voltage ( V th) degradation on the stress oxide field and stress temperature as well as investigation of the Arrhenius plot for the devices. The temperature insensitivity during short stress time of 1 ms indicates absence of generated defects and presence of preexisting defects. It is also observed that significant defects are generated in the gate stack subsequent to NBTI. The slope obtained from the V th degradation analysis at 1 ks and 375°C shows that changing the SiO2 interfacial layer thickness affects the V th degradation by 96.16% more than changing the HfO2 thickness and by 80.67% more than changing the metal gate thickness. It is also found that the NBTI effect depends on process design considerations, specifically the boron concentration in the highly doped drain, the metal gate work function, and the halo doping concentration; it was observed that higher boron dose and high metal work function may lead to higher V th degradation. However, the halo doping concentration in the advanced 32-nm structure has an insignificant effect on NBTI.

  11. Advances in large, transportable, highly spin-polarized, solid HD targets operable in the frozen-spin mode in a 1-4K temperature environment

    Science.gov (United States)

    Lewis, Aaron Paul

    The development of large, portable highly spin-polarized solid HD targets has been in progress at Syracuse University for the past 5 years. These targets are scheduled for deployment at Brookhaven National Laboratory, bearing the acronym SPHICE (Spin-Polarized Hydrogen Ice), for studies of the electro-magnetic spin structure of the nucleus via scattering of polarized gammas from the HD polarized protons and deuterons. The target work has just reached the milestone demonstration of the complete system, including polarization of triple targets containing 4 moles of solid HD, aging of these targets so that they retain their polarization for months under storage at a temperature of 1.3K and in an 8 Tesla field, and for at least a week at operational conditions of 1.3K and 0.7 Tesla in an in-beam cryostat. Cold-transfers of the polarized targets to a storage cryostat have been successfully carried out, and the storage cryostat has been trucked from Syracuse to BNL with one polarized target, sufficient to test the in-beam operations there. The complete system is presented here, with emphasis on innovations for engagement and disengagement of multiple targets, a solution to the challenge of attaining sufficiently strong RF fields in the large volume probe coils at acceptable power dissipation in the cables, and the polarization production and monitoring in the highly inhomogeneous magnetic fields owing to the multiple targets and the large dimensions of the targets. In this first multiple target production and extraction-to-storage cycle, air-ice accumulation in the dilution refrigerator due to repetitive use of cold sliding o-ring seals resulted in a rupture of one of the inserted targets, and a consequent partial thermal short from a solid HD ice bridge. The o-ring fault was cured with double evacuatable o-ring seals, and the air-ice was successfully cleaned out. However, the refrigerator operating base temperature was substantially higher than that normally obtained

  12. A 2000-year European Mean Summer Temperature Reconstruction from the PAGES 2k Regional Network and Comparison to Millennium-Length Forced Model Simulations

    Science.gov (United States)

    Smerdon, J. E.; Büntgen, U.; Ljungqvist, F. C.; Esper, J.; Fernández-Donado, L.; Gonzalez-Rouco, F. J.; Luterbacher, J.; McCarroll, D.; Wagner, S.; Wahl, E. R.; Wanner, H.; Werner, J.; Zorita, E.

    2012-12-01

    A reconstruction of mean European summer (JJA) land temperatures from 138 B.C.E. to 2003 C.E. is presented and compared to 37 forced transient simulations of the last millennium from coupled General Circulation Models (CGCMs). Eleven annually resolved tree-ring and documentary records from ten European countries/regions were used for the reconstruction and compiled as part of the Euro_Med working group contribution to the PAGES 2k Regional Network. Records were selected based upon their summer temperature signal, annual resolution, and time-continuous sampling. All tree-ring data were detrended using the Regional Curve Standardization (RCS) method to retain low-frequency variance in the resulting mean chronologies. The calibration time series was the area-weighted JJA temperature computed from the CRUTEM4v dataset over a European land domain (35°-70°N, 10°W-40°E). A nested 'Composite-Plus-Scale' reconstruction was derived using nine nests reflecting the availability of predictors back in time. Each nest was calculated by standardizing the available predictor series over the calibration interval, and subsequently calculating a weighted composite in which each proxy was multiplied by its correlation with the target index. The CPS methodology was implemented using a resampling scheme that uses 104 years for calibration. The initial calibration period extended from 1850-1953 C.E. and was incremented by one year until reaching the final period of 1900-2003 C.E., yielding a total of 51 reconstructions for each nest. Within each calibration step, the 50 years excluded from calibration were used for validation. Validation statistics across all reconstruction ensemble members within each nest indicate skillful reconstructions (RE: 0.42-0.64; CE: 0.26-0.54) and are all above the maximum validation statistics achieved in an ensemble of red noise benchmarking experiments. Warm periods in the derived reconstruction during the 1st, 2nd, and 7th-12th centuries compare to

  13. Hydrolysis of cellulose to glucose at the low temperature of 423 K with CaFe2O4-based solid catalyst.

    Science.gov (United States)

    Zhang, Fan; Fang, Zhen

    2012-11-01

    Weakly magnetic CaFe(2)O(4) was synthesized by calcination of the hydroxides co-precipitated from aqueous Ca(NO(3))(2)·6H(2)O and Fe(NO(3))(3)·9H(2)O solutions in the presence of urea. Microcrystalline cellulose was treated with ionic liquid (IL) [AMIM]Cl (1-allyl-3-methylimidazolium chloride) and hydrolyzed in the presence of the catalyst at 423K. No IL contamination was detected in the treated cellulose by energy-dispersive X-ray spectrometry (EDX). A maximum hydrolysis yield of 49.8% and glucose selectivity of 74.1% was obtained. The catalyst was separated and reused four times, showing only a slight decrease in activity. The catalyst was stable and only minor leaching into water occurred as indicated by inductively coupled plasma atomic emission spectrometry (ICP), X-ray diffraction (XRD), and temperature programmed desorption (TPD) measurements and a neutral pH after reactions. Hydrolysis of cellulose with CaFe(2)O(4) catalyst combined with [AMIM]Cl pretreatment is a green, energy-saving and efficient process. Copyright © 2012 Elsevier Ltd. All rights reserved.

  14. A study of the x-irradiated Cs sub 5 H sub 3 (SO sub 4) sub 4 centre dot H sub 2 O crystal by EPR in the 80-415 K temperature range

    CERN Document Server

    Waplak, S; Baranov, A I; Shuvalov, L A

    1997-01-01

    The EPR spectra of the x-irradiated fast proton conductor Cs sub 5 H sub 3 (SO sub 4) sub 4 centre dot H sub 2 O were investigated in the temperature range of 80-415 K. Two kinds of paramagnetic SO sub 4 sup - centres with different proton configurations below about 370 K and freeze-out behaviour of one of them below about 200 K were observed. The role of acid proton dynamics with respect to the glassy-like transition is discussed. (author)

  15. Effect of temperature and solvent composition on acid dissociation equilibria, I: Sequenced {sup s}{sub s}pK{sub a} determination of compounds commonly used as buffers in high performance liquid chromatography coupled to mass spectroscopy detection

    Energy Technology Data Exchange (ETDEWEB)

    Padro, Juan M.; Acquaviva, Agustin; Tascon, Marcos [Laboratorio de Separaciones Analiticas, Division Quimica Analitica, Universidad Nacional de La Plata y CIDEPINT, 47 y 115, (1900) La Plata (Argentina); Gagliardi, Leonardo G., E-mail: leogagliardi@quimica.unlp.edu.ar [Laboratorio de Separaciones Analiticas, Division Quimica Analitica, Universidad Nacional de La Plata y CIDEPINT, 47 y 115, (1900) La Plata (Argentina); Castells, Cecilia B., E-mail: castells@isis.unlp.edu.ar [Laboratorio de Separaciones Analiticas, Division Quimica Analitica, Universidad Nacional de La Plata y CIDEPINT, 47 y 115, (1900) La Plata (Argentina)

    2012-05-06

    Highlights: Black-Right-Pointing-Pointer We developed a rapid potentiometric method for sequential pK{sub a} determinations. Black-Right-Pointing-Pointer We measured pK{sub a} of buffers from 0 to 90% (v/v) acetonitrile/water and from 20 to 60 Degree-Sign C. Black-Right-Pointing-Pointer Sequences of 42 pK{sub a}-data spanned over a wide solvent composition range needed 2 h. Black-Right-Pointing-Pointer We measured pK{sub a} of formic acid and triethylamine/HCl in up to 90% (v/v) acetonitrile. Black-Right-Pointing-Pointer The high-throughput method was applied to obtain pK{sub a} of two common buffers in LC/MS. - Abstract: A new automated and rapid potentiometric method for determining the effect of organic-solvent composition on pK{sub a} has been developed. It is based on the measurements of pH values of buffer solutions of variable solvent compositions using a combined glass electrode. Additions of small volumes of one precisely thermostated solution into another, both containing exactly the same analytical concentrations of the buffer components, can produce continuous changes in the solvent composition. Two sequences of potential measurements, one of increasing and the other of decreasing solvent content, are sufficient to obtain the pK{sub a} values of the acidic compound within the complete solvent-composition range in about 2 h. The experimental design, procedures, and calculations needed to convert the measured pH into the thermodynamic pK{sub a} values are thoroughly discussed. This rapid and automated method allows the systematic study of the effect of solvent compositions and temperatures on the pK{sub a}. It has been applied to study the dissociation constants of two monoprotic acids: formic acid and triethylamine:HCl in acetonitrile/water mixtures within the range from 0 to 90% (v/v) at temperatures between 20 Degree-Sign C and 60 Degree-Sign C. These volatile compounds are frequently used to control the pH of the mobile phase in HPLC, especially in

  16. Mechanical properties of the high-entropy alloy Al0.5CoCrCuFeNi in various structural states at temperatures of 0.5-300 K

    Science.gov (United States)

    Tabachnikova, E. D.; Laktionova, M. A.; Semerenko, Yu. A.; Shumilin, S. E.; Podolskiy, A. V.; Tikhonovsky, M. A.; Miskuf, J.; Csach, K.

    2017-09-01

    The mechanical properties and fracture characteristics of the high-entropy alloy Al0.5CoCrCuFeNi are studied in different structural states (cast and after two heat treatments) at temperatures of 0.5-300 K with quasistatic deformation by uniaxial compression and distension. Mechanical resonance spectroscopy is used to measure the temperature variations of the Young modulus in the different structural states. It is found that heat treatment of the samples leads to an increase (by roughly 25%) in the Young modulus, the nominal yield point τ0.2, and the deforming stress. The form of the deformation curves is analyzed. The temperature interval for the transition from smooth to discontinuous plastic flow is determined. For the cast state the differences in τ0.2 under tension and compression are determined, an anomalous temperature dependence of τ0.2 (for temperatures in the 0.5-4.2 K range) is discovered, and thermal activation analysis of the experimental data yields empirical estimates for the parameters of the interactions of dislocations with local barriers. After heat treatment the samples break up into two parts under compression, as opposed to the cast state, where the samples acquire a "barrel" shape during compression. It is found that fracture of the heat treated samples at temperatures of 300-4.2 K has a viscous character.

  17. Ta{sub 2}O{sub 5}-based high-K dielectric thin films from solution processed at low temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Frunză, Raluca C., E-mail: raluca.frunza@ijs.si [Electronic Ceramics Department, Jožef Stefan Institute, Jamova cesta 39, 1000 Ljubljana (Slovenia); Jožef Stefan International Postgraduate School, Jamova cesta 39, 1000 Ljubljana (Slovenia); Kmet, Brigita [Electronic Ceramics Department, Jožef Stefan Institute, Jamova cesta 39, 1000 Ljubljana (Slovenia); Jankovec, Marko; Topič, Marko [Faculty of Electrical Engineering, University of Ljubljana, Tržaška cesta 25, 1000 Ljubljana (Slovenia); Malič, Barbara [Electronic Ceramics Department, Jožef Stefan Institute, Jamova cesta 39, 1000 Ljubljana (Slovenia)

    2014-02-01

    Highlights: • Ta{sub 2}O{sub 5}–Al{sub 2}O{sub 3}–SiO{sub 2} (Ta:Al:Si = 8:1:1 atomic ratio) and Ta{sub 2}O{sub 5} films were processed from solutions. • The XRD-amorphous films, heated at or below 400 °C, are smooth (RMS < 0.5 nm). • The dielectric permittivity of the single- and mixed-oxide films heated at 400 °C is 27 and 22, respectively. • The current–voltage characteristics of the mixed-oxide films reveal the Poole–Frenkel behaviour. - Abstract: Ta{sub 2}O{sub 5}-based thin films were prepared by chemical solution deposition at temperatures not exceeding 400 °C. The aim of the work was to investigate the properties of high-K dielectric films of the ternary composition Ta{sub 2}O{sub 5}–Al{sub 2}O{sub 3}–SiO{sub 2} with the Ta:Al:Si = 8:1:1 atomic ratio. Pure Ta{sub 2}O{sub 5} samples were also prepared. All thin films were amorphous, and had smooth and flat surfaces with the average roughness of below 0.5 nm. The mixed oxide samples heated between 300 °C and 400 °C showed little difference in the dielectric permittivity with the values ranging from about 19 to 22. The Ta{sub 2}O{sub 5} film heated at 400 °C exhibited the highest permittivity of about 27. The current–voltage measurements revealed considerably improved characteristics of the Ta{sub 2}O{sub 5}–Al{sub 2}O{sub 3}–SiO{sub 2} samples within the investigated heating temperature range, with a significant overall decrease of the leakage currents in contrast to that of the pure Ta{sub 2}O{sub 5} thin films.

  18. Assimilation of MODIS Ice Surface Temperature and Albedo into the Snow and Ice Model CROCUS Over the Greenland Ice Sheet Along the K-transect Stations

    Science.gov (United States)

    Navari, M.; Margulis, S. A.; Bateni, S. M.; Alexander, P. M.; Tedesco, M.

    2016-12-01

    Estimating the Greenland Ice Sheet (GrIS) surface mass balance (SMB) is an important component of current and future projections of sea level rise. In situ measurement provides direct estimates of the SMB, but are inherently limited by their spatial extent and representativeness. Given this limitation, physically based regional climate models (RCMs) are critical for understanding GrIS physical processes and estimating of the GrIS SMB. However, the uncertainty in estimates of SMB from RCMs is still high. Surface remote sensing (RS) has been used as a complimentary tool to characterize various aspects related to the SMB. The difficulty of using these data streams is that the links between them and the SMB terms are most often indirect and implicit. Given the lack of in situ information, imperfect models, and under-utilized RS data it is critical to merge the available data in a systematic way to better characterize the spatial and temporal variation of the GrIS SMB. This work proposes a data assimilation (DA) framework that yields temporally-continuous and physically consistent SMB estimates that benefit from state-of-the-art models and relevant remote sensing data streams. Ice surface temperature (IST) is the most important factor that regulates partitioning of the net radiation into the subsurface snow/ice, sensible and latent heat fluxes and plays a key role in runoff generation. Therefore it can be expected that a better estimate of surface temperature from a data assimilation system would contribute to a better estimate of surface mass fluxes. Albedo plays an important role in the surface energy balance of the GrIS. However, even advanced albedo modules are not adequate to simulate albedo over the GrIS. Therefore, merging remotely sensed albedo product into a physically based model has a potential to improve the estimates of the GrIS SMB. In this work a MODIS-derived IST and a 16-day albedo product are independently assimilated into the snow and ice model CROCUS

  19. Genomic organization and functional diversification of two warm-temperature-acclimation-associated 65-kDa protein genes in rockbream (Oplegnathus fasciatus; Perciformes).

    Science.gov (United States)

    Lee, Sang Yoon; Kim, Byoung Soo; Noh, Choong Hwan; Nam, Yoon Kwon

    2014-03-01

    Two paralogue genes of warm-temperature-acclimation-associated 65-kDa protein were characterized and their mRNA expression patterns during various experimental stimulations were examined in the rockbream (Oplegnathus fasciatus; Perciformes). Rockbream Wap65 isoforms (rbWap65-1 and rbWap65-2) share basically common structural features with other teleostean orthologues and human hemopexin (HPX) at both amino acid (conserved cysteine and histidine residues) and genomic levels (ten-exon structure), although the rbWap65-2 reveals more homologous characteristics to human HPX than does rbWap65-1 isoform. Southern blot analysis indicates that each rbWap65 isoform exists as a single copy gene in the rockbream genome. Both rbWap65 genes were predicted to possess various transcription factor (TF) binding motifs related with stress and innate immunity in their 5ʹ-upstream regions, in which inflammation-related motifs were more highlighted in the rbWap65-2 than in rbWap65-1. Based on the RT-PCR assay, the liver-predominant expression pattern was more apparent in rbWap65-1 than rbWap65-2 isoform. During thermal elevation, clear upregulation was found only for the rbWap65-1. In contrast, immune stimulations (bacterial challenges, viral infection and iron overload) activated more preferentially the rbWap65-2 isoform in overall, although the inducibility was affected by the kinds of stimulators and tissue types. Taken together, our data suggest that the two paralogue rbWap65 isoforms have experienced subfunctionalization and/or neofunctionalization during their evolutionary history, in which the rbWap65-2 has retained closer, functional orthology to the human HPX while the rbWap65-1 have been diversified to be more related with thermal acclimation physiology. Copyright © 2014 Elsevier Ltd. All rights reserved.

  20. Assessing the Salting-Out Behavior of 2,4-Dinitrobenzaldehyde and 2,6-Dinitrobenzaldehyde from Solubility Values in Pure Water and Seawater at Temperatures between (280 and 313) K

    Science.gov (United States)

    2011-05-12

    Assessing the Salting-out Behavior of Nitrobenzene, 2- Nitrotoluene , and 3- Nitrotoluene from Solubility Values in Pure Water and Seawater at...Temperatures Between (277 and 314)K. J. Chem. Eng. Data 2009, 54, 1231–1235. (17) Sada, E.; Kito, S.; Ito, Y. Solubility of Toluene in Aqueous Salt Solutions

  1. Low temperature vibrational spectra, lattice dynamics, and phase transitions in some potassium hexahalometallates: K2[XY6] with X=Sn or Te and Y=Cl or Br

    DEFF Research Database (Denmark)

    Chodos, Steven L.; Berg, Rolf W.

    1979-01-01

    This paper deals with the observation and identification of phonon frequencies resulting from the low temperature phase transitions in K2XY6 crystals. By means of a simple lattice dynamical model, the vibrational Raman and IR data available in the literature and obtained here have been analyzed. ...

  2. Densities and volume properties of (water + tert-butanol) over the temperature range of (274.15 to 348.15) K at pressure of 0.1 MPa

    Energy Technology Data Exchange (ETDEWEB)

    Egorov, Gennadiy I., E-mail: gie@isc-ras.r [Laboratory of Structure and Dynamics of Molecular and Ion-Molecular Solutions, Institute of Solution Chemistry, Russian Academy of Sciences, 1 Akademicheskaya Street, 153045 Ivanovo (Russian Federation); Makarov, Dmitriy M. [Laboratory of Structure and Dynamics of Molecular and Ion-Molecular Solutions, Institute of Solution Chemistry, Russian Academy of Sciences, 1 Akademicheskaya Street, 153045 Ivanovo (Russian Federation)

    2011-03-15

    The densities of {l_brace}water (1) + tert-butanol (2){r_brace} binary mixture were measured over the temperature range (274.15 to 348.15) K at atmospheric pressure using 'Anton Paar' digital vibrating-tube densimeter. Density measurements were carried out over the whole concentration range at (308.15 to 348.15) K. The following volume parameters were calculated: excess molar volumes and thermal isobaric expansivities of the mixture, partial molar volumes and partial molar thermal isobaric expansivities of the components. Concentration dependences of excess molar volumes were fitted with Redlich-Kister equation. The results of partial molar volume calculations using four equations were compared. It was established that for low alcohol concentrations at T {<=} 208 K the inflection points at x{sub 2} {approx} 0.02 were observed at concentration dependences of specific volume. The concentration dependences of partial molar volumes of both water and tert-butanol had extremes at low alcohol content. The temperature dependence of partial molar volumes of water had some inversion at x{sub 2} {approx} 0.65. The temperature dependence of partial molar volumes of tert-butanol at infinite dilution had minimum at {approx}288 K. It was discovered that concentration dependences of thermal isobaric expansivities of the mixture at small alcohol content and low temperatures passed through minimum.

  3. Temperature dependence of the NO3 absorption cross-section above 298 K and determination of the equilibrium constant for NO3 + NO2 N2O5 at atmospherically relevant conditions.

    Science.gov (United States)

    Osthoff, Hans D; Pilling, Michael J; Ravishankara, A R; Brown, Steven S

    2007-11-21

    The reaction NO3 + NO2 N2O5 was studied over the 278-323 K temperature range. Concentrations of NO3, N2O5, and NO2 were measured simultaneously in a 3-channel cavity ring-down spectrometer. Equilibrium constants were determined over atmospherically relevant concentration ranges of the three species in both synthetic samples in the laboratory and ambient air samples in the field. A fit to the laboratory data yielded Keq = (5.1 +/- 0.8) x 10(-27) x e((10871 +/- 46)/7) cm3 molecule(-1). The temperature dependence of the NO3 absorption cross-section at 662 nm was investigated over the 298-388 K temperature range. The line width was found to be independent of temperature, in agreement with previous results. New data for the peak cross section (662.2 nm, vacuum wavelength) were combined with previous measurements in the 200 K-298 K region. A least-squares fit to the combined data gave sigma = [(4.582 +/- 0.096) - (0.00796 +/- 0.00031) x T] x 10(-17) cm2 molecule(-1).

  4. Temperature profiles from MBT casts from the CIRRUS and CUMULUS from Ocean Weather Station K (OWS-K) and M (OWS-M) in the North Atlantic Ocean from 01 January 1969 to 16 January 1970 (NODC Accession 7000939)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Bathythermograph data were collected from the CIRRUS and CUMULUS within a 1-mile radius of Ocean Weather Station K (4500N 01600W), M (6600N 00200E), and in transit....

  5. A high-resolution neutron powder diffraction investigation of galena (PbS) between 10 K and 350 K: no evidence for anomalies in the lattice parameters or atomic displacement parameters in galena or altaite (PbTe) at temperatures corresponding to the saturation of cation disorder.

    Science.gov (United States)

    Knight, K S

    2014-09-24

    The temperature dependences of the unit cell parameter and the atomic displacement parameters (adp) for galena (PbS) have been measured using high resolution neutron powder diffraction in the temperature interval 10-350 K. No evidence has been found for the anomalous behaviour recently reported in a total scattering study of galena, in which the temperature variation of both the unit cell and the adp for lead are reported to undergo a dramatic reduction at a temperature of ~250 K. The linear thermal expansion coefficient calculated from the powder diffraction study is found to be in excellent agreement with literature values over the entire temperature interval studied, and approximately 25% greater at room temperature than that determined by analysis of the pair distribution function (pdf) derived from the total scattering data. This discrepancy is shown to be attributable to a linear, temperature-dependent offset from the published temperatures in the total scattering study, and has arisen from the sample temperature being significantly lower than the experimental set point temperature. Applying this correction to the adps of the lead cation removes the anomalous temperature dependence and shows the pdf results are in agreement with the neutron powder diffraction results. Application of the identical temperature offsets to the results of the pdf analysis of data collected on altaite (PbTe) eliminates the anomalous behaviour in the unit cell and the adp for lead, bringing them in line with literature values. Contrary to the conclusions of the pdf analysis, adps for the lead cation in both galena and altaite can be described in terms of Debye-like behaviour and are consistent with the partial phonon density of states.

  6. Crystal structure and high-temperature properties of (Pr,Sr)2(Co,Mn)O4±δ with K2NiF4-type structure

    Science.gov (United States)

    Zharikova, E. V.; Rozova, M. G.; Kazakov, S. M.; Istomin, S. Ya.; Lyskov, N. V.; Antipov, E. V.

    2016-11-01

    Novel oxides PrSrCo1-yMnyO4±δ, 0.0≤y≤0.5 and Pr0.5Sr1.5Co1-yMnyO4±δ 0.3≤y≤0.5 with K2NiF4-type structure were synthesized. The crystal structure, oxygen content, thermal expansion and electrical conductivity of the obtained compounds were examined. A chemical titration showed that PrSrCo0.5Mn0.5O4±δ is slightly overstoichiometric (δ=0.03(2)), while Pr0.5Sr1.5Co0.5Mn0.5O4±δ is oxygen deficient (δ=-0.05(2)). Thermal expansion behavior was studied by both dilatometry and high-temperature X-ray powder diffraction in the temperature range of 298-1173 K in air. Pr0.5Sr1.5Co0.5Mn0.5O3.95(2) exhibited linear thermal expansion along the a- and c-axes over the studied temperature range with thermal expansion coefficients (TECs) were 17.5 ppm K-1 and 17.8 ppm K-1, respectively. For PrSrCo0.5Mn0.5O4.03(2) two regions (298-600 K and 600-1173 K) observed, where the TEC along the a-axis decreased from 12.7 ppm K-1 to 10.4 ppm K-1 whereas the TEC along the c-axis increased from 14.5 ppm K-1 to 26.7 ppm K-1. Both compounds demonstrated lower in comparison with undoped PrSrCoO4 values of electrical conductivity of 7 S/cm for PrSrCo0.5Mn0.5O4.03(2) and 23 S/cm for Pr0.5Sr1.5Co0.5Mn0.5O3.95(2) at 1173 K in air.

  7. Studies on volumetric properties of some saccharides in aqueous potassium chloride solutions over temperature range (288.15 to 318.15) K

    Energy Technology Data Exchange (ETDEWEB)

    Banipal, Parampaul K. [Department of Chemistry, Guru Nanak Dev University, Amritsar 143 005 (India)], E-mail: pkbanipal@yahoo.com; Chahal, Amanpreet K. [Department of Chemistry, Guru Nanak Dev University, Amritsar 143 005 (India); Banipal, Tarlok S. [Department of Applied Chemistry, Guru Nanak Dev University, Amritsar 143 005 (India)

    2009-04-15

    The standard partial molar volumes, V{sub 2}{sup {infinity}} at infinite dilution of monosaccharides; D(+)-xylose, D(-)-arabinose, D(-)-ribose, D(+)-mannose, D(+)-galactose, D(-)-fructose and D(+)-glucose, disaccharides; D(+)-melibiose, D(+)-cellobiose, D(+)-maltose monohydrate, D(+)-trehalose dihydrate, D(+)-lactose monohydrate and sucrose, trisaccharide; D(+)-raffinose pentahydrate, methylglycosides; {alpha}-methyl-D(+)-glucoside, methyl-{alpha}-D-xylopyranoside and methyl-{beta}-D-xylopyranoside have been determined in water and in aqueous solutions of potassium chloride (0.5, 1.0, 2.0, and 3.0) mol . kg{sup -1} at T = (288.15, 298.15, 308.15, and 318.15) K from density measurements employing a vibrating-tube densimeter. These results have been utilized to determine the corresponding standard partial molar volumes of transfer, {delta}{sub t}V{sub 2}{sup {infinity}} for the transfer of various saccharides from water to aqueous potassium chloride solutions. The standard transfer volumes have been found to be positive (except for {alpha}- and {beta}-methyl xylopyranosides in 0.5 mol . kg{sup -1} solutions of potassium chloride) whose magnitude increase with the concentration of potassium chloride as well as temperature for all the saccharides. Partial molar expansion coefficients, ({partial_derivative}V{sub 2}{sup {infinity}}/{partial_derivative}T){sub p} and the second derivative ({partial_derivative}{sup 2}V{sub 2}{sup {infinity}}/{partial_derivative}T{sup 2}){sub p} values have been estimated. Pair and higher order volumetric interaction coefficients have also been calculated from {delta}{sub t}V{sub 2}{sup {infinity}} by using the McMillan-Mayer theory. These parameters have been discussed in terms of the solute-cosolute interactions and are used to understand various mixing effects due to these interactions. The effect of substitution of -OH by glycosidic group, -OCH{sub 3} is also discussed. Attempt has also been made to discuss the stereochemical effects

  8. Rheological behaviour of some saccharides in aqueous potassium chloride solutions over temperature range (288.15 to 318.15) K

    Energy Technology Data Exchange (ETDEWEB)

    Banipal, Parampaul K., E-mail: pkbanipal@yahoo.co [Department of Chemistry, Guru Nanak Dev University, Amritsar 143005 (India); Chahal, Amanpreet K.; Singh, Vickramjeet [Department of Chemistry, Guru Nanak Dev University, Amritsar 143005 (India); Banipal, Tarlok S. [Department of Applied Chemistry, Guru Nanak Dev University, Amritsar 143005 (India)

    2010-08-15

    The viscosities, {eta} of mono-, di-, tri-saccharides and methylglycosides, viz., D(+)-xylose (XYL), D(-)-arabinose (ARA), D(-)-ribose (RIB), D(-)-fructose (FRU), D(+)-galactose (GAL), D(+)-mannose (MAN), D(+)-glucose (GLU), D(+)-melibiose (MEL), D(+)-cellobiose (CEL), D(+)-lactose monohydrate (LAC), D(+)-maltose monohydrate (MAL), D(+)-trehalose dihydrate (TRE), sucrose (SUC), D(+)-raffinose pentahydrate (RAF), {alpha}-methyl-D(+)-glucoside ({alpha}-Me-GLU), methyl-{alpha}-D-xylopyranoside (Me-{alpha}-XYL), and methyl-{beta}-D-xylopyranoside (Me-{beta}-XYL) in water and in (0.5, 1.0, 2.0, and 3.0) mol . kg{sup -1} aqueous solutions of potassium chloride (KCl) have been determined at T = (288.15, 298.15, 308.15, and 318.15) K from efflux time measurements by using a capillary viscometer. Densities used to determine viscosities have been reported earlier. The viscosity data have been utilized to determine the viscosity B-coefficients employing the Jones-Dole equation at different temperatures. From these data, the viscosity B-coefficients of transfer, {Delta}{sub t}B have been estimated for the transfer of various saccharides/methylglycosides from water to aqueous potassium chloride solutions. The {Delta}{sub t}B values have been found to be positive, whose magnitude increases with the increase in concentration of potassium chloride in all cases. The dB/dT coefficients, pair, {eta}{sub AB} and triplet, {eta}{sub ABB} viscometric interaction coefficients have also been determined. Gibbs free energies of activation and related thermodynamic parameters of activation of viscous flow have been determined employing Feakin's transition-state theory. The signs and magnitudes of various parameters have been discussed in terms of solute-solute and solute-solvent interactions occurring in these solutions. The effect of substitution of -OH by methoxy group, -OCH{sub 3} has also been discussed.

  9. Electron attachment to halomethanes at high temperature: CH2Cl2, CF2Cl2, CH3Cl, and CF3Cl attachment rate constants up to 1100 K

    Science.gov (United States)

    Miller, Thomas M.; Friedman, Jeffrey F.; Schaffer, Linda C.; Viggiano, A. A.

    2009-08-01

    We have used a high-temperature flowing-afterglow Langmuir-probe apparatus to measure rate constants for electron attachment to halomethanes which attach electrons very inefficiently at room temperature, yielding Cl- ion product. We studied CH2Cl2 (495-973 K), CF2Cl2 (291-1105 K), and CF3Cl (524-1004 K) and include our recent measurement for CH3Cl (700-1100 K) in the discussion of the electron attachment results. The measured attachment rate constants show Arrhenius behavior in the temperature ranges examined, from which estimates of rate constants at 300 K may be made: CH2Cl2 (1.8×10-13 cm3 s-1), CH3Cl (1.1×10-17 cm3 s-1), and CF3Cl (4.2×10-14 cm3 s-1), all of which are difficult to measure directly. In the case of CF2Cl2, the room temperature rate constant was sufficiently large to be measured (1.6×10-9 cm3 s-1). The Arrhenius plots yield activation energies for the attachment reactions: 390±50 meV (CH2Cl2), 124±20 meV (CF2Cl2), 670±70 meV (CH3Cl), and 406±50 meV (CF3Cl). Comparisons are made with existing data where available. G3 calculations were carried out to obtain reaction energetics. They show that the parent anions of CH2Cl2 CF2Cl2, CH3Cl, and CF3Cl are stable, though CH3Cl- exists only as an electrostatically bound complex.

  10. Stark broadening parameter tables for K VIII and K IX

    Directory of Open Access Journals (Sweden)

    Dimitrijević M.S.

    1998-01-01

    Full Text Available Using a semiclassical approach, we have calculated electron−, proton−, and He III−impact line widths and shifts for 4 K VIII and 30 K IX multiplets as a function of temperature and perturber density.

  11. Active Thermometry Based DS18B20 Temperature Sensor Network for Offshore Pipeline Scour Monitoring Using K-Means Clustering Algorithm

    OpenAIRE

    Zhao, Xuefeng; Li, Weijie; Zhou, Lei; Song, Gang-Bing; Ba, Qin; Ou, Jinping

    2013-01-01

    This work presents an offshore pipeline scour monitoring sensor network system based on active thermometry. The system consists of thermal cables, data acquisition unit, and data processing unit. As the thermal cables emit heats, the distributed DS18B20 digital temperature sensors record temperature information over time. The scour-induced exposure and free spanning can be identified by analyzing the temperature curves. Pipeline exposure and free-spanning experiments were carried out in labor...

  12. Structure and Superconducting Properties of TlCan-1Ba2CunO2n+3 Thin Films with Zero Resistance at Temperatures above 100 K

    Science.gov (United States)

    Huang, T. C.; Lee, W. Y.; Lee, V. Y.; Karimi, R.

    1988-08-01

    New superconducting TlCan-1Ba2CunO2n+3 thin films have been analyzed by the X-ray diffraction and four-point probe techniques. The films consist mainly of a single TlCa2Ba2Cu3O9 phase or a mixture of the TlCa2Ba2O9 and TlCaBa2Cu2O7 phases with the c-axis preferentially oriented perpendicular to the film surface. The TlCa2Ba2Cu3O9 film grown on an asymmetrically cut yttrium-stabilized ZrO2 (YSZ) substrate has the highest superconducting transition with on-set Tc near 120 K and zero resistance at 116 K. The TlCa2Ba2Cu3O9 film deposited on a SrTiO3 (100) substrate has a slightly lower transition with zero resistance at 104 K probably because of stacking faults. The film composed of both the TlCa2Ba2Cu3O9 and TlCaBa2Cu2O7 phases and grown on YSZ has a double transition with on-set Tc near 118 K and 107 K, and zero resistance at 102 K.

  13. Influence of temperature on the (liquid + liquid) equilibria of {l_brace}3-methyl pentane + cyclopentane + methanol{r_brace} ternary system at T = (293.15, 297.15, and 299.15) K

    Energy Technology Data Exchange (ETDEWEB)

    Gramajo de Doz, Monica B. [Departamento de Fisica, Facultad de Ciencias Exactas y Tecnologia, Universidad Nacional de Tucuman, Avenida Independencia 1800, 4000 Tucuman (Argentina)], E-mail: mgramajo@herrera.unt.edu.ar; Cases, Alicia M.; Bonatti, Carlos M.; Solimo, Horacio N. [Departamento de Fisica, Facultad de Ciencias Exactas y Tecnologia, Universidad Nacional de Tucuman, Avenida Independencia 1800, 4000 Tucuman (Argentina)

    2009-11-15

    In order to show the influence of temperature on the (liquid + liquid) equilibria (LLE) of the {l_brace}3-methyl pentane (1) + cyclopentane (2) + methanol (3){r_brace} ternary system, equilibrium results at T = (293.15, 297.15, and 299.15) K are reported. The effect of the temperature on the (liquid + liquid) equilibrium is determined and discussed. Experimental results show that this ternary system is completely homogeneous beyond T = 300 K. All chemicals were quantified by gas chromatography using a thermal conductivity detector. The tie line results were satisfactorily correlated by the Othmer and Tobias method, and the plait point coordinates for the three temperatures were estimated. Experimental values for the ternary system are compared with values calculated by the NRTL and UNIQUAC equations, and predicted by means of the UNIFAC group contribution method. It is found that the UNIQUAC and NRTL models provide similar good correlations of the solubility curve at these three temperatures. Finally, the UNIFAC model predicts binodal band type curves in the range of temperatures studied here, similar to those observed for systems classified by Treybal as type 2, instead of type 1 as experimentally observed. Distribution coefficients were also analysed through distribution curves.

  14. Boiling temperature measurement for water, methanol, ethanol and their binary mixtures in the presence of a hydrochloric or acetic salt of mono-, di- or tri-ethanolamine at 101.3 kPa

    Energy Technology Data Exchange (ETDEWEB)

    Wang Junfeng [State Key Lab. of Chem. Resource Eng, College of Chem. Eng., Beijing Univ. of Chem. Tech. Beijing 100029 (China)], E-mail: Licx@mail.buct.edu.cn; Li Xuemei; Meng Hong [College of Chem. Eng.., Beijing Univ. of Chem. Tech. Beijing 100029 (China); Li Chunxi [State Key Lab. of Chem. Resource Eng, College of Chem. Eng., Beijing Univ. of Chem. Tech. Beijing 100029 (China); Wang Zihao [College of Chem. Eng., Beijing Univ. of Chem. Tech. Beijing 100029 (China)

    2009-02-15

    The boiling temperature at atmospheric pressure were measured for 12 binary systems within the range T = (316 to 379) K and 7 ternary systems using a dual circulation. The systems studied contained water, methanol or ethanol with the following ionic liquids (ILs): monoethanolammonium acetate ([HEMA][Ac]), diethanolammonium acetate ([HDEA][Ac]), triethanolammonium acetate ([HTEA][Ac]) and diethanolammonium chloride ([HDEA]Cl). The experimental VLE results of the IL-containing binary systems were correlated by NRTL equation, and the binary NRTL parameters were used for the prediction of VLE of ternary systems with average absolute deviation of 0.73 K in boiling temperature. The results indicate that [HDEA]Cl can be used as an efficient solvent for the extractive distillation of (ethanol + water) mixture due to its notable salting-out effect, which lower the vapour pressure of water, increase the volatility of ethanol and eliminate the azeotropic phenomenon of the (water + ethanol) mixture at definite IL concentration.

  15. Title: Elucidation of Environmental Fate of Artificial Sweeteners (Aspartame, Acesulfame K and Saccharin) by Determining Bimolecular Rate Constants with Hydroxyl Radical at Various pH and Temperature Conditions and Possible Reaction By-Products

    Science.gov (United States)

    Teraji, T.; Arakaki, T.; Suzuka, T.

    2012-12-01

    Use of artificial sweeteners in beverages and food has been rapidly increasing because of their non-calorie nature. In Japan, aspartame, acesulfame K and sucralose are among the most widely used artificial sweeteners. Because the artificial sweeteners are not metabolized in human bodies, they are directly excreted into the environment without chemical transformations. We initiated a study to better understand the fate of artificial sweeteners in the marine environment. The hydroxyl radical (OH), the most potent reactive oxygen species, reacts with various compounds and determines the environmental oxidation capacity and the life-time of many compounds. The steady-state OH concentration and the reaction rate constants between the compound and OH are used to estimate the life-time of the compound. In this study, we determine the bimolecular rate constants between aspartame, acefulfame K and saccharin and OH at various pH and temperature conditions using a competition kinetics technique. We use hydrogen peroxide as a photochemical source of OH. Bimolecular rate constant we obtained so far for aspartame was (2.6±1.2)×109 M-1 s-1 at pH = 3.0 and (4.9±2.3)×109 M-1 s-1 at pH = 5.5. Little effect was seen by changing the temperatures between 15 and 40 oC. Activation energy (Ea) was calculated to be -1.0 kJ mol-1 at pH = 3.0, +8.5 kJ mol-1 at pH = 5.5, which could be regarded as zero. We will report bimolecular rate constants at different pHs and temperatures for acesulfame K and saccharin, as well. Possible reaction by-products for aspartame will be also reported. We will further discuss the fate of aspartame in the coastal environment.

  16. Excess enthalpies of binary mixtures of 1-hexene with some branched alkanes at the temperature 298.15 K[Excess enthalpy; Binary mixture; 1-Hexene; Branched alkanes; Liebermann-Fried model

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Zhaohui; Benson, George C.; Lu, Benjamin C.-Y. E-mail: lu@eng.uottawa.ca

    2004-01-01

    Measurements of excess molar enthalpies at the temperature 298.15 K in a flow microcalorimeter are reported for the five binary mixtures formed by mixing 1-hexene with the branched alkanes: 2-methylpentane, 3-methylpentane, 2,2-dimethylbutane, 2,3-dimethylbutane, and 2,2,4-trimethylpentane. Smooth Redlich-Kister representations of the results are described. It was found that the Liebermann-Fried model also provided good representations of the results.

  17. Rate constants for the gas-phase reactions of OH radicals with CH3CHF2 and CHCl2CF3 over the temperature range 295-388 K

    DEFF Research Database (Denmark)

    Nielsen, O.J.

    1991-01-01

    Rate constants for the reactions of OH radicals with CH3CHF2 and CHCl2CF3 have been determined over the temperature range 295-388 K and a total pressure of 1 atm. The OH rate data were obtained using the absolute rate technique of pulse radiolysis combined with kinetic spectroscopy. The data can...... and in the light of the important role CH3CHF2 and CHCl2CF3 play as alternatives to the fully halogenated chlorofluorocarbons....

  18. 373 K Superconductors

    CERN Document Server

    Kostadinov, Ivan Zahariev

    2016-01-01

    Experimental evidence of superconductors with critical temperatures above $373\\:K$ is presented. In a family of different compounds we demonstrate the superconductor state, the transition to normal state above $387\\:K$, an intermediate $242\\:K$ superconductor, susceptibility up to $350\\:K$, $I-V$ curves at $4.2\\:K$ in magnetic field of $12\\:T$ and current up to $60\\:A$, $300\\:K$ Josephson Junctions and Shapiro steps with radiation of $5\\:GHz$ to $21\\:THz$, $300\\:K$ tapes tests with high currents up to $3000\\:A$ and many $THz$ images of coins and washers. Due to a pending patent, the exact chemical characterization and technological processes for these materials are temporarily withheld and will be presented elsewhere.

  19. Prediction of the critical reduced electric field strength for carbon dioxide and its mixtures with 50% O2 and 50% H2 from Boltzmann analysis for gas temperatures up to 3500 K at atmospheric pressure

    Science.gov (United States)

    Zhao, Hu; Li, Xingwen; Jia, Shenli; Murphy, Anthony B.

    2014-08-01

    This paper provides theoretical calculations that predict the dielectric breakdown properties of carbon dioxide (CO2) and its mixtures with 50% O2 and 50% H2 for a gas temperature range of 300-3500 K at 0.1 MPa. CO2 is one of the most likely candidates for an environment-friendly arc-quenching medium to replace SF6 in high-voltage circuit breakers. Initially, the electron energy distribution function (EEDF) is derived by solving the Boltzmann equation under the zero-dimensional two-term spherical harmonic approximation. Then the reduced ionization and attachment coefficients are obtained, based on the calculated EEDF. Finally, the critical reduced electric field strength (E/N)cr, which is defined as the value for which total ionization reactions are equal to total attachment reactions, is obtained and analysed. The results demonstrate the superior breakdown properties of a 50% CO2-50% O2 mixture to those of both pure CO2 and 50% CO2-50% H2. Nearly no deviation in (E/N)cr is found in a 50% CO2-50% O2 mixture for gas temperatures up to 2500 K, and although there is clear reduction as the gas temperature is increased further to 3500 K, the value remains higher than that of pure CO2.

  20. Dynamics of 4-oxo-TEMPO-d16-15N nitroxide-propylene glycol system studied by ESR and ESE in liquid and glassy state in temperature range 10-295 K

    Science.gov (United States)

    Goslar, Janina; Hoffmann, Stanislaw K.; Lijewski, Stefan

    2016-08-01

    ESR spectra and electron spin relaxation of nitroxide radical in 4-oxo-TEMPO-d16-15N in propylene glycol were studied at X-band in the temperature range 10-295 K. The spin-lattice relaxation in the liquid viscous state determined from the resonance line shape is governed by three mechanisms occurring during isotropic molecular reorientations. In the glassy state below 200 K the spin-lattice relaxation, phase relaxation and electron spin echo envelope modulations (ESEEM) were studied by pulse spin echo technique using 2-pulse and 3-pulse induced signals. Electron spin-lattice relaxation is governed by a single non-phonon relaxation process produced by localized oscillators of energy 76 cm-1. Electron spin dephasing is dominated by a molecular motion producing a resonance-type peak in the temperature dependence of the dephasing rate around 120 K. The origin of the peak is discussed and a simple method for the peak shape analysis is proposed, which gives the activation energy of a thermally activated motion Ea = 7.8 kJ/mol and correlation time τ0 = 10-8 s. The spin echo amplitude is strongly modulated and FT spectrum contains a doublet of lines centered around the 2D nuclei Zeeman frequency. The splitting into the doublet is discussed as due to a weak hyperfine coupling of nitroxide unpaired electron with deuterium of reorienting CD3 groups.

  1. K Agashe

    Indian Academy of Sciences (India)

    K Agashe. Articles written in Pramana – Journal of Physics. Volume 60 Issue 2 February 2003 pp 383-394. Working group report: Collider and B physics · Amitava Datta K Sridhar K Abe K Agashe R Aleksan B C Allanach S Chakraborti D Choudhury Asesh Krishna Datta Anindya Datta A Djouadi D Ghosh R M Godbole M ...

  2. WATER TEMPERATURE and other data from USS RICHMOND K. TURNER, USS CUSHING and other platforms from 1991-01-14 to 1992-10-29 (NCEI Accession 9300065)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The water depth and temperature data was collected from eight ships by the US Navy. The data was collected from January 14, 1991 to October 29, 1992. 32 envelopes of...

  3. Determination of the rate constant for the OH(X2Π) + OH(X2Π) → H2O + O(3P) reaction over the temperature range 295 to 701 K.

    Science.gov (United States)

    Altinay, Gokhan; Macdonald, R Glen

    2014-01-09

    The rate constant for the radical-radical reaction OH(X(2)Π) + OH(X(2)Π) → H2O + O((3)P) has been measured over the temperature and pressure ranges 295-701 K and 2-12 Torr, respectively, in mixtures of CF4, N2O, and H2O. The OH radical was produced by the 193 nm laser photolysis of N2O. The resulting O((1)D) atoms reacted rapidly with H2O to produce the OH radical. The OH radical was detected by high-resolution time-resolved infrared absorption spectroscopy using a single Λ-doublet component of the OH(1,0) P1e/f(4.5) fundamental vibrational transition. A detailed kinetic model was used to determine the reaction rate constant as a function of temperature. These experiments were conducted in a new temperature controlled reaction chamber. The values of the measured rate constants are quite similar to the previous measurements from this laboratory of Bahng and Macdonald (J. Phys. Chem. A 2007 , 111 , 3850 - 3861); however, they cover a much larger temperature range. The results of the present work do not agree with recent measurements of Sangwan and Krasnoperov (J. Phys. Chem. A 2012 , 116 , 11817 - 11822). At 295 K the rate constant of the title reaction was found to be (2.52 ± 0.63) × 10(-12) cm(3) molecule(-1) s(-1), where the uncertainty includes both experimental scatter and an estimate of systematic errors at the 95% confidence limit. Over the temperature range of the experiments, the rate constant can be represented by k1a = 4.79 × 10(-18)T(1.79) exp(879.0/T) cm(3) molecule(-1) s(-1) with a uncertainty of ±24% at the 2σ level, including experimental scatter and systematic error.

  4. Involvement of the CasK/R two-component system in optimal unsaturation of the Bacillus cereus fatty acids during low-temperature growth

    NARCIS (Netherlands)

    Diomandé, Sara Esther; Nguyen-the, Christophe; Abee, Tjakko; Tempelaars, M.H.; Broussolle, Véronique; Brillard, Julien

    2015-01-01

    Bacillus cereus sensu lato is composed of a set of ubiquitous strains including human pathogens that can survive a range of food processing conditions, grow in refrigerated food, and sometimes cause food poisoning. We previously identified the two-component system CasK/R that plays a key role in

  5. Persistent-current switch for pancake coils of rare earth-barium-copper-oxide high-temperature superconductor: Design and test results of a double-pancake coil operated in liquid nitrogen (77–65 K) and in solid nitrogen (60–57 K)

    Energy Technology Data Exchange (ETDEWEB)

    Qu, Timing; Michael, Philip C.; Bascuñán, Juan; Iwasa, Yukikazu, E-mail: iwasa@jokaku.mit.edu [Francis Bitter Magnet Laboratory, Plasma Science and Fusion Center, Massachusetts Institute of Technology, 170 Albany Street, Cambridge, Massachusetts 02139 (United States); Voccio, John [Wentworth Institute of Technology, 550 Huntington Ave, Boston, Massachusetts 02115 (United States); Hahn, Seungyong [National High Magnetic Field Laboratory, Florida State University, Tallahassee, 2031 Paul Dirac Drive, Florida 32310 (United States)

    2016-08-22

    We present design and test results of a superconducting persistent current switch (PCS) for pancake coils of rare-earth-barium-copper-oxide, REBCO, high-temperature superconductor (HTS). Here, a REBCO double-pancake (DP) coil, 152-mm ID, 168-mm OD, 12-mm high, was wound with a no-insulation technique. We converted a ∼10-cm long section in the outermost layer of each pancake to a PCS. The DP coil was operated in liquid nitrogen (77–65 K) and in solid nitrogen (60–57 K). Over the operating temperature ranges of this experiment, the normal-state PCS enabled the DP coil to be energized; thereupon, the PCS resumed the superconducting state and the DP coil field decayed with a time constant of 100 h, which would have been nearly infinite, i.e., persistent-mode operation, were the joint across the coil terminals superconducting.

  6. New experimental perspectives for soft x-ray absorption spectroscopies at ultra-low temperatures below 50 mK and in high magnetic fields up to 7 T

    Science.gov (United States)

    Beeck, T.; Baev, I.; Gieschen, S.; Meyer, H.; Meyer, S.; Palutke, S.; Feulner, P.; Uhlig, K.; Martins, M.; Wurth, W.

    2016-04-01

    A new ultra-low temperature experiment including a superconducting vector magnet has been developed for soft x-ray absorption spectroscopy experiments at third generation synchrotron light sources. The sample is cooled below 50 mK by a cryogen free 3He-4He dilution refrigerator. At the same time, magnetic fields of up to ±7 T in the horizontal direction and ±0.5 T in the vertical direction can be applied by a superconducting vector magnet. The setup allows to study ex situ and in situ prepared samples, offered by an attached UHV preparation chamber with load lock. The transfer of the prepared samples between the preparation section and the dilution refrigerator is carried out under cryogenic temperatures. First commissioning studies have been carried out at the Variable Polarization XUV Beamline P04 at PETRA III and the influence of the incident photon beam to the sample temperature has been studied.

  7. A study of the temperature dependence of the infrared absorption cross-sections of 2,2,3,3,3-pentafluoropropanol in the range of 298-362 K

    Science.gov (United States)

    Godin, Paul J.; Cabaj, Alex; Xu, Li-Hong; Le Bris, Karine; Strong, Kimberly

    2017-01-01

    Absorption cross-sections of 2,2,3,3,3-pentafluoropropanol (PFPO) were derived from Fourier transform infrared spectra recorded from 565 to 3400 cm-1 with a resolution of 0.1 cm-1 over a temperature range of 298-362 K. These results were compared to previously published theoretical density functional theory (DFT) calculations and experimental measurements made at room temperature. We find good agreement between our experimentally derived results, DFT calculations, and previously published data. The only temperature dependence observed was in the centroid shift of the 850-1500 cm-1 band and in the amplitude of some of the absorption peaks. However, this temperature dependence does not result in a significant trend in integrated band strength as a function of temperature. We calculate an average integrated band strength of (1.991±0.001)×10-16 cm molecule-1 for PFPO over the spectral range studied. Radiative efficiencies (REs) and the global warming potential (GWP) for PFPO were also derived. We find an average RE of 0.2603 ± 0.0007 Wm-2ppbv-1 and a GWP100 of 19.8. The calculated radiative efficiencies show that no dependence on temperature and our findings are consistent with previous studies, increasing our confidence in the value of the GWP of PFPO.

  8. Development of a nano-tesla magnetic field shielded chamber and highly precise AC-susceptibility measurement coil at μK temperatures

    Science.gov (United States)

    Kumar, Anil; Prakash, Om; Ramakrishanan, S.

    2014-04-01

    A special sample measurement chamber has been developed to perform experiments at ultralow temperatures and ultralow magnetic field. A high permeability material known as cryoperm 10 and Pb is used to shield the measurement space consisting of the signal detecting set-up and the sample. The detecting setup consists of a very sensitive susceptibility coil wound on OFHC Cu bobbin.

  9. Vitamin K

    Science.gov (United States)

    Vitamins are substances that your body needs to grow and develop normally. Vitamin K helps your body by making proteins for ... blood clotting. If you don't have enough vitamin K, you may bleed too much. Newborns have ...

  10. Vitamin K

    Science.gov (United States)

    ... diabetes (Antidiabetes drugs)Vitamin K1 might decrease blood sugar. Diabetes medications are also used to lower blood sugar. Taking vitamin K1 along with diabetes medications might cause your blood sugar to go ...

  11. K Vidyasagar

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Chemical Sciences. K Vidyasagar. Articles written in Journal of Chemical Sciences. Volume 112 Issue 3 June 2000 pp 417-417. Solid state chemistry of new polysulphides in A/Sn/S (A = Na, K, Rb) systems · M Suseela Devi K Vidyasagar · More Details Fulltext PDF. Volume 115 Issue 5-6 ...

  12. New hardware and software platform for experiments on a HUBER-5042 X-ray diffractometer with a DISPLEX DE-202 helium cryostat in the temperature range of 20-300 K

    Science.gov (United States)

    Dudka, A. P.; Antipin, A. M.; Verin, I. A.

    2017-09-01

    Huber-5042 diffractometer with a closed-cycle Displex DE-202 helium cryostat is a unique scientific instrument for carrying out X-ray diffraction experiments when studying the single crystal structure in the temperature range of 20-300 K. To make the service life longer and develop new experimental techniques, the diffractometer control is transferred to a new hardware and software platform. To this end, a modern computer; a new detector reader unit; and new control interfaces for stepper motors, temperature controller, and cryostat vacuum pumping system are used. The system for cooling the X-ray tube, the high-voltage generator, and the helium compressor and pump for maintaining the desired vacuum in the cryostat are replaced. The system for controlling the primary beam shutter is upgraded. A biological shielding is installed. The new program tools, which use the Linux Ubuntu operating system and SPEC constructor, include a set of drivers for control units through the aforementioned interfaces. A program for searching reflections from a sample using fast continuous scanning and a priori information about crystal is written. Thus, the software package for carrying out the complete cycle of precise diffraction experiment (from determining the crystal unit cell to calculating the integral reflection intensities) is upgraded. High quality of the experimental data obtained on this equipment is confirmed in a number of studies in the temperature range from 20 to 300 K.

  13. Volumetric and transport properties of binary liquid mixtures of N-methylacetamide with lactones at temperatures (303.15 to 318.15) K

    Energy Technology Data Exchange (ETDEWEB)

    Boodida, Sathyanarayana; Bachu, Ranjith Kumar; Patwari, Murali Krishna [Department of Chemistry, Kakatiya University, Warangal 506 009 (India); Nallani, Satyanarayana [Department of Chemistry, Kakatiya University, Warangal 506 009 (India)], E-mail: ns_narayana@yahoo.com

    2008-09-15

    The values of density ({rho}), viscosity ({eta}) and speed of sound (u) have been measured for binary liquid mixtures of {gamma}-butyrolactone (GBL), {delta}-valerolactone (DVL), and {epsilon}-caprolactone (ECL) with N-methylacetamide (NMA) over the whole composition range at T = (303.15 to 318.15) K and atmospheric pressure. From these data, excess molar volume (V{sup E}), deviation in viscosity ({delta}{eta}), and deviation in isentropic compressibility ({delta}{kappa}{sub s}), are calculated. The results are fitted to a Redlich-Kister type polynomial equation to derive binary coefficients and standard deviations.

  14. A New Bayesian Gridded European Summer Temperature Reconstruction from the PAGES 2k Regional Network and Comparison to Millennium-Length Forced Model Simulations

    Science.gov (United States)

    Werner, J.; Büntgen, U.; Ljungqvist, F. C.; Esper, J.; Fernández-Donado, L.; Gonzalez-Rouco, F. J.; Luterbacher, J.; McCarroll, D.; Smerdon, J. E.; Wagner, S.; Wahl, E. R.; Wanner, H.; Zorita, E.

    2012-12-01

    We present a new gridded (5°x5°) European summer (JJA) temperature reconstruction back to 750 C.E. and compare it to an ensemble of millennium length forced transient climate model (general circulation models, GCMs) runs. The reconstruction is based on ten long, high quality tree ring records and one composite documentary record, all of them annually resolved. The spatial coverage spans the area 41°N-68°N and 1°E-25°E. Instrumental data used are the land mass grid cells of the CRUTEM4v dataset. Seasonal summer means were calculated from the data over the period 1850-2010 C.E. as anomalies wrt. the 1961-90 C.E. climatology. The climate field reconstruction was performed using Bayesian inference together with a localized stochastic description of the underlying processes (Tingley and Huybers 2010a,b; Werner et al. 2012). To this end, chains using different initial conditions as well as subsets of the data were run to estimate the posterior distributions. From these results, predictive experiments using the full proxy data were made, resulting in a multivariate distribution of temperature reconstructions from 750 - 2003 C.E. The mean of this distribution is the optimal estimate of the gridded annual summer temperature anomalies, the width delivers impartial reconstruction uncertainties. The derived reconstruction is compared with independent long instrumental and proxy data on decadal-to-centennial time scales. The simulations are grouped in two categories depending on the magnitude of change in solar forcing used to drive the model. We then compare the new gridded reconstruction with the GCM results, focusing on two key periods over the last one and a half millennia: the Little Ice Age (LIA) and the Medieval Climate Anomaly (MCA). While all data show higher medieval temperatures and cooler temperatures during the LIA, the spatial distribution of anomalies and the range of values differ. When comparing the key periods to present day climate, both periods were

  15. Atomistic simulations of the equation of state and hybridization of liquid carbon at a temperature of 6000 K in the pressure range of 1-25 GPa

    Science.gov (United States)

    Dozhdikov, V. S.; Basharin, A. Yu.; Levashov, P. R.; Minakov, D. V.

    2017-12-01

    The equation of state and the structure of liquid carbon are studied by molecular simulation. Both classical and quantum molecular dynamics (QMD) are used to calculate the equation of state and the distribution of chemical bonds at 6000 K in the pressure range 1-25 GPa. Our calculations and results of other authors show that liquid carbon has a fairly low density on the order of 1.2-1.35 g/cm3 at pressures about 1 GPa. Owing to the coordination number analysis, this fact can be attributed to the high content of sp1-bonded atoms (more than 50% according to our ab initio computations). Six empirical potentials have been tested in order to describe the density dependence of pressure and structure at 6000 K. As a result, only one potential, ReaxFF/lg, was able to reproduce the QMD simulations for both the equation of state and the fraction of sp1, sp2, sp3-bonded atoms.

  16. (Vapour + liquid) equilibrium in (N,N-dimethylacetamide + methanol + water) at the temperature 313.15 K[N,N-Dimethylacetamide; Water; Methanol; Amides; Binary mixtures; Ternary mixtures; (Vapour+liquid) equilibrium; Excess Gibbs free energy; Correlation

    Energy Technology Data Exchange (ETDEWEB)

    Zielkiewicz, Jan. E-mail: jaz@altis.chem.pg.gda.pl

    2003-12-01

    Total vapour pressures, measured at the temperature 313.15 K, are reported for the ternary mixture (N,N-dimethylacetamide + methanol + water), and for binary constituents (N,N-dimethylacetamide + methanol) and (N,N-dimethylacetamide + water). The present results are compared with previously obtained data for binary mixtures (amide + water) and (amide + methanol), where amide=N-methylformamide, N,N-dimethylformamide, N-methyl-acetamide, 2-pyrrolidinone and N-methylpyrrolidinone. Moreover, it was found that excess Gibbs free energy of mixing for binary mixtures varies roughly linearly with the molar volume of amide.

  17. Temperature-tuned Maxwell-Boltzmann neutron spectra for kT ranging from 30 up to 50 keV for nuclear astrophysics studies.

    Science.gov (United States)

    Martín-Hernández, G; Mastinu, P F; Praena, J; Dzysiuk, N; Capote Noy, R; Pignatari, M

    2012-08-01

    The need of neutron capture cross section measurements for astrophysics motivates present work, where calculations to generate stellar neutron spectra at different temperatures are performed. The accelerator-based (7)Li(p,n)(7)Be reaction is used. Shaping the proton beam energy and the sample covering a specific solid angle, neutron activation for measuring stellar-averaged capture cross section can be done. High-quality Maxwell-Boltzmann neutron spectra are predicted. Assuming a general behavior of the neutron capture cross section a weighted fit of the spectrum to Maxwell-Boltzmann distributions is successfully introduced. Copyright © 2012 Elsevier Ltd. All rights reserved.

  18. Tunable exchange bias effect in magnetic Bi0.9Gd0.1Fe0.9Ti0.1O3 nanoparticles at temperatures up to 250K

    DEFF Research Database (Denmark)

    Basith, M. A.; Khan, F. A.; Ahmmad, Bashir

    2015-01-01

    The exchange bias (EB) effect has been observed in magnetic Bi0.9Gd0.1Fe0.9Ti0.1O3 nanoparticles.The influence of magnetic field cooling on the exchange bias effect has also been investigated. The magnitude of the exchange bias field (HEB) increases with the cooling magnetic field, showing...... that the strength of the exchange bias effect is tunable by the field cooling. The HEB values are also found to be dependent on the temperature. This magnetically tunable exchange bias obtained at temperatures up to 250K in Bi0.9Gd0.1Fe0.9Ti0.1O3 nanoparticles may be worthwhile for potential applications....

  19. Structure of the RbTi{sub 0.98}Zr{sub 0.02}OPO{sub 4} single crystal at temperatures of 293 and 105 K

    Energy Technology Data Exchange (ETDEWEB)

    Alekseeva, O. A., E-mail: olalex@ns.crys.ras.ru; Dudka, A. P.; Novikova, N. E.; Sorokina, N. I. [Russian Academy of Sciences, Shubnikov Institute of Crystallography (Russian Federation); Agapova, E. I.; Voronkova, V. I. [Lomonosov Moscow State University (Russian Federation)

    2008-07-15

    This paper reports on the results of precision X-ray structural investigations of a RbTi{sub 0.98}Zr{sub 0.02}OPO{sub 4} single crystal at temperatures of 293 and 105 K. It is established that the observed decrease in the temperature of the ferroelectric phase transition in RbTiOPO{sub 4} crystals doped with zirconium is associated with the increase in the Rb-O bond lengths. The structural factors responsible for the decrease in the electrical conductivity in these crystals are revealed. An analysis is made of the structure of the helical channels which in crystals of this family are considered to be a decisive factor for the manifestation of superionic conduction. It is shown that, in structures of the KTiOPO{sub 4} (KTP) type, the migration of ions in channels is most hindered inside the cavities.

  20. New experimental methodology, setup and LabView program for accurate absolute thermoelectric power and electrical resistivity measurements between 25 and 1600 K: application to pure copper, platinum, tungsten, and nickel at very high temperatures.

    Science.gov (United States)

    Abadlia, L; Gasser, F; Khalouk, K; Mayoufi, M; Gasser, J G

    2014-09-01

    In this paper we describe an experimental setup designed to measure simultaneously and very accurately the resistivity and the absolute thermoelectric power, also called absolute thermopower or absolute Seebeck coefficient, of solid and liquid conductors/semiconductors over a wide range of temperatures (room temperature to 1600 K in present work). A careful analysis of the existing experimental data allowed us to extend the absolute thermoelectric power scale of platinum to the range 0-1800 K with two new polynomial expressions. The experimental device is controlled by a LabView program. A detailed description of the accurate dynamic measurement methodology is given in this paper. We measure the absolute thermoelectric power and the electrical resistivity and deduce with a good accuracy the thermal conductivity using the relations between the three electronic transport coefficients, going beyond the classical Wiedemann-Franz law. We use this experimental setup and methodology to give new very accurate results for pure copper, platinum, and nickel especially at very high temperatures. But resistivity and absolute thermopower measurement can be more than an objective in itself. Resistivity characterizes the bulk of a material while absolute thermoelectric power characterizes the material at the point where the electrical contact is established with a couple of metallic elements (forming a thermocouple). In a forthcoming paper we will show that the measurement of resistivity and absolute thermoelectric power characterizes advantageously the (change of) phase, probably as well as DSC (if not better), since the change of phases can be easily followed during several hours/days at constant temperature.

  1. New experimental methodology, setup and LabView program for accurate absolute thermoelectric power and electrical resistivity measurements between 25 and 1600 K: Application to pure copper, platinum, tungsten, and nickel at very high temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Abadlia, L.; Mayoufi, M. [Laboratoire de Chimie des Matériaux Inorganiques, Université Badji-Mokhtar Annaba, BP12, 23000 Annaba (Algeria); Gasser, F.; Khalouk, K.; Gasser, J. G., E-mail: jean-georges.gasser@univ-lorraine.fr [Laboratoire de Chimie et Physique - Approche Multi-échelle des Milieux Complexes (LCP-A2MC) Institut de Chimie, Physique et Matériaux, Université de Lorraine, 1 Boulevard Arago - 57078 Metz cedex 3 (France)

    2014-09-15

    In this paper we describe an experimental setup designed to measure simultaneously and very accurately the resistivity and the absolute thermoelectric power, also called absolute thermopower or absolute Seebeck coefficient, of solid and liquid conductors/semiconductors over a wide range of temperatures (room temperature to 1600 K in present work). A careful analysis of the existing experimental data allowed us to extend the absolute thermoelectric power scale of platinum to the range 0-1800 K with two new polynomial expressions. The experimental device is controlled by a LabView program. A detailed description of the accurate dynamic measurement methodology is given in this paper. We measure the absolute thermoelectric power and the electrical resistivity and deduce with a good accuracy the thermal conductivity using the relations between the three electronic transport coefficients, going beyond the classical Wiedemann-Franz law. We use this experimental setup and methodology to give new very accurate results for pure copper, platinum, and nickel especially at very high temperatures. But resistivity and absolute thermopower measurement can be more than an objective in itself. Resistivity characterizes the bulk of a material while absolute thermoelectric power characterizes the material at the point where the electrical contact is established with a couple of metallic elements (forming a thermocouple). In a forthcoming paper we will show that the measurement of resistivity and absolute thermoelectric power characterizes advantageously the (change of) phase, probably as well as DSC (if not better), since the change of phases can be easily followed during several hours/days at constant temperature.

  2. New experimental methodology, setup and LabView program for accurate absolute thermoelectric power and electrical resistivity measurements between 25 and 1600 K: Application to pure copper, platinum, tungsten, and nickel at very high temperatures

    Science.gov (United States)

    Abadlia, L.; Gasser, F.; Khalouk, K.; Mayoufi, M.; Gasser, J. G.

    2014-09-01

    In this paper we describe an experimental setup designed to measure simultaneously and very accurately the resistivity and the absolute thermoelectric power, also called absolute thermopower or absolute Seebeck coefficient, of solid and liquid conductors/semiconductors over a wide range of temperatures (room temperature to 1600 K in present work). A careful analysis of the existing experimental data allowed us to extend the absolute thermoelectric power scale of platinum to the range 0-1800 K with two new polynomial expressions. The experimental device is controlled by a LabView program. A detailed description of the accurate dynamic measurement methodology is given in this paper. We measure the absolute thermoelectric power and the electrical resistivity and deduce with a good accuracy the thermal conductivity using the relations between the three electronic transport coefficients, going beyond the classical Wiedemann-Franz law. We use this experimental setup and methodology to give new very accurate results for pure copper, platinum, and nickel especially at very high temperatures. But resistivity and absolute thermopower measurement can be more than an objective in itself. Resistivity characterizes the bulk of a material while absolute thermoelectric power characterizes the material at the point where the electrical contact is established with a couple of metallic elements (forming a thermocouple). In a forthcoming paper we will show that the measurement of resistivity and absolute thermoelectric power characterizes advantageously the (change of) phase, probably as well as DSC (if not better), since the change of phases can be easily followed during several hours/days at constant temperature.

  3. Synthesis and characterization of K(Ta(x)Nb(1_x))O3 particles by high temperature mixing method under hydrothermal and solvothermal conditions.

    Science.gov (United States)

    Gu, Honghui; Zhu, Kongjun; Qiu, Jinhao; Ji, Hongli; Cao, Yang; Jin, Jiamei

    2013-02-01

    KTa(x)Nb(1_x)O3 (KTN) particles with an orthorhombic perovskite structure were synthesized via a high temperature mixing method (HTMM) under hydrothermal and solvothermal conditions. The obtained products were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), transmission electron microscopy (TEM), selected area electron diffraction (SAED), and high-resolution transmission electron microcopy (HRTEM). The influences of alkaline concentration and Ta doping amounts on the phase structure and morphology of the obtained powders were investigated. The results showed that KTN powders could be solvothermally prepared when the KOH concentration is as low as 0.5 M. In comparison with the hydrothermal process, supercritical isopropanol plays an important role in synthesizing KTN particles under milder conditions. The KTa(0.4)Nb(0.6)O3 particles solvothermally synthesized in isopropanol are made of well crystallized and single crystalline particles with a size of about 100-200 nm. Room temperature PL studies excited at different wavelengths reveal five emission bands centered at about 421 nm, 446 nm, 468 nm, 488 nm, and 498 nm, respectively. The supercritical process proposed here provides a new potential route for synthesizing other perovskite-type materials.

  4. Operation of Silicon, Diamond and liquid Helium Detectors in the range of Room Temperature to 1.9 K and after an Irradiation Dose of several Mega Gray

    CERN Document Server

    Kurfuerst, C; Dehning, B; Eisel, T; Sapinski, M; Eremin, V

    2013-01-01

    At the triplet magnets, close to the interaction regions of the Large Hadron Collider (LHC), the current Beam Loss Monitoring (BLM) system is sensitive to the debris from the collision points. For future beams, with higher energy and intensity the expected increase in luminosity implicate an increase of the debris from interaction products covering the quench-provoking beam losses from the primary proton beams. The investigated option is to locate the detectors as close as possible to the superconducting coil, where the signal ratio of both is optimal. Therefore the detectors have to be located inside the cold mass of the superconducting magnets in superfluid helium at 1.9 Kelvin. Past measurements have shown that a liquid helium ionisation chamber, diamond and silicon detectors are promising candidates for cryogenic beam loss monitors. The carrier parameter, drift velocity, and the leakage current changes will be shown as a function of temperature. New high irradiation test beam measurements at room temperat...

  5. K Anantheshwara

    Indian Academy of Sciences (India)

    Home; Journals; Sadhana. K Anantheshwara. Articles written in Sadhana. Volume 33 Issue 3 June 2008 pp 221-226. Effect of friction on the performance of inertial slider · K Anantheshwara N S Murali M S Bobji · More Details Abstract Fulltext PDF. Inertial sliders are friction based drives used to position with a resolution of a ...

  6. K Ramachandran

    Indian Academy of Sciences (India)

    K Ramachandran. Articles written in Resonance – Journal of Science Education. Volume 10 Issue 7 July 2005 pp 73-84 Classroom. Two Dimensional Potential Mapping – Monte Carlo Simulation · J Meena Devi K Ramachandran · More Details Fulltext PDF. Volume 14 Issue 11 November 2009 pp 1102-1110 Classroom.

  7. K Balachandran

    Indian Academy of Sciences (India)

    Home; Journals; Proceedings – Mathematical Sciences. K Balachandran. Articles written in Proceedings – Mathematical Sciences. Volume 110 Issue 2 May 2000 pp 225-232. Existence of Solutions of Nonlinear Integrodifferential Equations of Sobolev Type with Nonlocal Condition in Banach Spaces · K Balachandran K ...

  8. K Sivan

    Indian Academy of Sciences (India)

    Home; Journals; Sadhana. K Sivan. Articles written in Sadhana. Volume 29 Issue 2 April 2004 pp 175-188. Performance evaluation of multi-sensor data-fusion systems in launch vehicles · B N Suresh K Sivan · More Details Abstract Fulltext PDF. In this paper, the utilization of multi-sensors of different types, their ...

  9. K Fatima

    Indian Academy of Sciences (India)

    Home; Journals; Sadhana. K Fatima. Articles written in Sadhana. Volume 28 Issue 5 October 2003 pp 957-974. Nano finish grinding of brittle materials using electrolytic in-process dressing (ELID) technique · M Rahman A Senthil Kumar H S Lim K Fatima · More Details Abstract Fulltext PDF. Recent developments in grinding ...

  10. K Porsezian

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education. K Porsezian. Articles written in Resonance – Journal of Science Education. Volume 15 Issue 7 July 2010 pp 643-666 General Article. Elements of Optical Solitons: An Overview · V C Kuriakose K Porsezian · More Details Fulltext PDF. Volume 17 Issue 2 February ...

  11. K Bhaskar

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education. K Bhaskar. Articles written in Resonance – Journal of Science Education. Volume 17 Issue 8 August 2012 pp 748-758 General Article. C–Past, Present, and Future – A Perspective · K Bhaskar · More Details Fulltext PDF ...

  12. Aloke K Mathur

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Earth System Science. Aloke K Mathur. Articles written in Journal of Earth System Science. Volume 120 Issue 3 June 2011 pp 337-345. Atmospheric correction for sea surface temperature retrieval from single thermal channel radiometer data onboard Kalpana satellite · Naveen R Shahi Neeraj ...

  13. K Praveen Kumar

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Earth System Science. K Praveen Kumar. Articles written in Journal of Earth System Science. Volume 120 Issue 5 October 2011 pp 807-823. Long-term variations in outgoing long-wave radiation (OLR), convective available potential energy (CAPE) and temperature in the tropopause region over ...

  14. Ternary liquid-liquid equilibria of Eugenol + Isobutanol + H2O and β-Caryophyllene + Isobutanol + H2O systems at temperatures 303.15 and 323.15 K

    Science.gov (United States)

    Parameswari, Zahrida D.; Kurniawan, Andre M.; Wibawa, Gede; Kuswandi, Kuswandi

    2017-05-01

    The liquid-liquid equilibrium (LLE) data of ternary Eugenol + Isobutanol + H2O and β-Caryophyllene + Isobutanol + H2O systems were measured at temperatures of 303.15 K and 323.15 K. Equilibrium cell with water jacket for keeping the temperature was used. Equilibrium data were obtained by stirring the mixture for 4 hours and settled for 20 hours to allow the system reach the equilibrium state. Samples of organic and aqueous phases were analyzed using Gas Chromatography. All the measured data were correlated using NRTL and UNIQUAC models. The reliability of the models is tested by comparison of calculated equilibrium compositions with experimental data in terms of root mean square deviations (RMSD). The system exhibited type II phase behaviour from immiscible area. It has two pairs miscible components (Eugenol + Isobutanol and β-Caryophyllene + Isobutanol), two pairs partially miscible components (Eugenol + H2O and Isobutanol + H2O) and one pair immiscible components (β-Caryophyllene + H2O). The temperatures on this system have small effect on immiscible zone and slope of tie lines. Based on experiment and calculation results, Eugenol + Isobutanol + H2O system has been successfully represented slightly better using UNIQUAC model with average values of RMSD is 2.0842% meanwhile NRTL model has higher value of RMSD that is 2.1359%, and β-Caryophyllene + Isobutanol + H2O system has been successfully represented better using UNIQUAC model with average values of RMSD is 2.1521% meanwhile NRTL model has higher value of RMSD that is 3.2976%.

  15. In-situ studies on the micro-structure evolution of A2W2O7 (A = Li, Na, K) during melting by high temperature Raman spectroscopy and density functional theory

    Science.gov (United States)

    Wang, Jian; You, Jinglin; Wang, Min; Lu, Liming; Wan, Songming; Sobol, A. A.

    2017-10-01

    In-situ high temperature Raman spectroscopic (HTRS) technique in combination with density functional theory (DFT) analysis has been adopted to investigate the micro-structure of solid and molten A2W2O7 (A = Li, Na, K). The [WO6] octahedra were found to be connected to each other by corner and edge sharing in the crystalline Li2W2O7 and K2W2O7 compounds. In the crystal lattice of Na2W2O7, on the other hand, the [WO4] tetrahedra and [WO6] octahedra were found to coexist and paired by corner sharing. Although the structural diversity has clearly led to distinct Raman spectra of the crystalline A2W2O7 compounds, the spectra of their melts tended to be analogous, showing the typical vibration modes of (W2O7)2 - dimer. A mechanism was then proposed to explain the structure evolution occurring during the melting process of A2W2O7. The effect of A+ cation on the Raman bands of (W2O7)2 - dimer in molten A2W2O7 has also been investigated. Both the wavenumber and full width at half-height (FWHH) of the characteristic band assigned to the symmetrical stretching vibration mode of Wsbnd Onb (non-bridging oxygen) in (W2O7)2 - were found to decrease in the sequence of Li+, Na+ and K+, indicating the cation effect on the mean bond length and its distribution range of Wsbnd Onb. In addition, the relative intensity of this band was also influenced by the cation and it was increased in the order of Li2W2O7, Na2W2O7 and K2W2O7, which has been explained by the charge transfer process and confirmed by Mulliken overlap population analysis.

  16. Phase behaviour for the (carbon dioxide + 2-phenoxyethyl acrylate) and (carbon dioxide + 2-phenoxyethyl methacrylate) systems at temperatures from (313.2 to 393.2) K and pressures from (5 to 31) MPa

    Energy Technology Data Exchange (ETDEWEB)

    Byun, Hun-Soo, E-mail: hsbyun@chonnam.ac.k [School of Biotechnology and Chemical Engineering, Chonnam National University, Yeosu, Jeonnam 550-749 (Korea, Republic of); Jang, Yoon-Seok [School of Biotechnology and Chemical Engineering, Chonnam National University, Yeosu, Jeonnam 550-749 (Korea, Republic of); Yoo, Ki-Pung [Department of Chemical and Biological Engineering, Sogang University, Seoul 121-742 (Korea, Republic of)

    2010-06-15

    The solubility curves for the (carbon dioxide + 2-phenoxyethyl acrylate) and (carbon dioxide + 2-phenoxyethyl methacrylate) systems were determined by a static view cell apparatus at five temperatures (313.2, 333.2, 353.2, 373.2, and 393.2) K as well as pressures up to 31.43 MPa. Two left bracecarbon dioxide + (meth)acrylateright brace systems had continuous critical mixture curves with maxima in pressure located between the critical temperatures of carbon dioxide and 2-phenoxyethyl (meth)acrylate. The solubility of 2-phenoxyethyl (meth)acrylate in the left bracecarbon dioxide + 2-phenoxyethyl (meth)acrylateright brace systems increases as the temperature increases at a fixed pressure. The (carbon dioxide + 2-phenoxyethyl acrylate) and (carbon dioxide + 2-phenoxyethyl methacrylate) systems exhibit type-I phase behaviour. The experimental results for the (carbon dioxide + 2-phenoxyethyl acrylate) and (carbon dioxide + 2-phenoxyethyl methacrylate) systems correlate with the Peng-Robinson equation of state using a van der Waals one-fluid mixing rule including two adjustable parameters. The critical properties of 2-phenoxyethyl acrylate and 2-phenoxyethyl methacrylate were predicted with the Joback and Lee-Kesler method.

  17. Charge Transfer Interaction and Hydrogen Bonding between Vitamine K1 and Dihydrovitamine K1

    Science.gov (United States)

    Nagahira, Yukio; Matsuki, Kazunori; Fukutome, Hideo

    1981-01-01

    We studied visible and infrared spectra, in particular their temperature dependence, of Vitamine K1 oil dissolving dihydrovitamine K1. Vitamine K1 and dihydrovitamine K1 were found to form charge transfer complexes and hydrogen bonds in the mixture. A co-crystal of Dihydrovitamine K1 and Vitamine K1 with charge transfer interaction and hydrogen bonding was shown to grow in a narrow temperature range near -20°C.

  18. Fault of the correction factor for pressure and temperature k{sub PT} in the atmospheric conditions of Dosimetric Calibration Lab. - LSCD of ININ - Mexico; Falla del factor de correcion por presion y temperatura k{sub PT} a las condiciones atmosfericas del LSCD-ININ-Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Alvarez R, Jose T.; Jesus Cejudo, A.; La Cruz H., Daniel de; Tovar M, Victor M., E-mail: trinidad.alvarez@inin.gob.mx, E-mail: jesus.cejudo@inin.gob.mx, E-mail: daniel.delacruz@inin.gob.mx, E-mail: victor.tovar@inin.gob.mx [Instituto Nacional de Investigaciones Nucleares (LSCD/ININ), Ocoyoacac (Mexico). Laboratorio Secundario de Calibracion Dosimetrica

    2013-07-01

    The realization of the operational quantities H*, Hp y/0 H'(0.07) for estimating the effective dose E, usually is done by measuring the air kerma Ka air within the field of ionizing radiation of interest and was subsequently applied appropriate conversion factors for both the quality of radiation and the operational quantity of interest. However, the SSDL in performing the Ka to environmental conditions of ININ (3000 m above sea level, P ∼ 710 hPa) with ionization chambers has found that the pressure correction factor and kPT temperature is not sufficient to correct the change in air density. Indeed, in the case of {sup 60}Co the discrepancy between the measurement of a primary standard graphite walls Ka (BEV CC01 be 131) and a side of the plastic walls (Exradin A12) is on the order of 0.4% for the case of the RX BIPM qualities to 100,135, 180 and 250 kV. It was found that for a camera model 30001 PTW (PMMA graphite wall) is needed an additional correction factor k PT ranging from 0.4% to 1.5%, correction factor calculated by MC simulation. For Sk of {sup 125}I brachytherapy sources was given an additional correction lower in 11% compared to conventional k{sub PT} value measured with a well chamber Standard Imaging HDR 1000 plus. Finally, it is in the process of studying the behavior of this additional correction factor to the case of {sup 137}Cs.

  19. Studies on the thermodynamics and solute–solvent interaction of Polyvinyl pyrrolidone wrapped single walled carbon nanotubes (PVP-SWNTs in water over temperature range 298.15–313.15 K

    Directory of Open Access Journals (Sweden)

    Malahah Mohamed

    2017-05-01

    Full Text Available The water solubilisation of single walled carbon nanotubes (SWNTs has been achieved by polymer wrapping. The present study aims at highlighting the solute–solvent interaction and thermodynamic parameters in the solubilisation of polyvinyl pyrrolidone wrapped single walled carbon nanotubes (PVP-SWNTs in water. Conductivity and density values of both PVP and PVP-SWNTs have been determined in water maintaining different concentrations (0.005–0.1 g/L at temperatures 298.15, 303.15, 308.15 and 313.15 K. The conductance values have been used to evaluate the limiting molar conductance (∧om and the activation energy (Es. From the density values, the limiting partial molar volumes and expansibilities have been calculated. The estimated parameters were discussed in terms of solute–solvent interactions.

  20. Phase relations and thermodynamics of the system Fe-Cr-0 in the temperature range of 1600 °C to 1825 °C (1873 to 2098 K) under strongly reducing conditions

    Science.gov (United States)

    Toker, N. Y.; Darken, L. S.; Muan, Arnulf

    1991-10-01

    Equilibrium relations involving alloy and oxide phases in the system Fe-Cr-O were determined in the temperature range from 1600 °C to 1825 °C (1873 to 2087 K). Compositions of coexisting alloy and spinel phases were established as a function of oxygen pressure by equilibrating liquid Fe-Cr alloys with iron chromite (Fe3-xCrxO4) solid solutions at 1600 °C and 1700 °C. Combinations of these experimental data and thermodynamic calculations were used to construct composition-oxygen pressure diagrams for the system at 1600 °C and 1700 °C. Additional runs for selected mixtures were made at still higher temperatures (1700 °C to 1825 °C), and thermodynamic parameters were derived for spinel-containing phase assemblages at temperatures up to 1865 °C. The spinel phases occurring in the present system are typically in the high-chromium range of the solid-solution series Fe3O4-Cr3O4, i.e., in the range between stoichiometric iron chromite (FeCr2O4) and Cr3O4. The activities of the various oxide components of the spinel solid solution at 1600 °C were calculated from experimentally determined parameters for coexisting alloy and spinel phases, as well as by statistical-mechanical modeling of the same spinel solid solution based on crystal-chemical considerations. The agreement between the two sets of results was excellent. Temperature variation of parameters characterizing the univariant equilibria spinel + Cr2O3 + alloy and spinel + alloy + liquid oxide was established. The univariant curves were found to display temperature maxima of 1715 °C ± 5 °C and approximately 1865 °C, respectively. In analogy with relations in the Cr-O system, the increase in divalent chromium of the liquid oxide phase with decreasing oxygen potential was identified as the main cause of the sharp decrease in liquidus temperatures of chromites in contact with Fe-Cr alloys of high Cr contents.

  1. Compressed liquid densities and excess molar volumes for (CO{sub 2} + 1-pentanol) binary system at temperatures from 313 to 363 K and pressures up to 25 MPa

    Energy Technology Data Exchange (ETDEWEB)

    Zuniga-Moreno, Abel [Instituto Politecnico Nacional, ESIQIE, Laboratorio de Termodinamica, Edif. Z, Secc. 6, 1er piso, UPALM Zacatenco, 07738, Lindavista, Mexico, D.F. (Mexico); Galicia-Luna, Luis A. [Instituto Politecnico Nacional, ESIQIE, Laboratorio de Termodinamica, Edif. Z, Secc. 6, 1er piso, UPALM Zacatenco, 07738, Lindavista, Mexico, D.F. (Mexico)], E-mail: lgalicial@ipn.mx; Sandler, Stanley I. [Department of Chemical Engineering, University of Delaware, Newark, DE 19716-3119 (United States)

    2008-02-15

    Measurements of compressed liquid densities for 1-pentanol and for {l_brace}CO{sub 2} (1) + 1-pentanol (2){r_brace} system were carried out at temperatures from 313 K to 363 K and pressures up to 25 MPa. Densities were measured for binary mixtures at 10 different compositions, x{sub 1} = 0.0816, 0.1347, 0.3624, 0.4651, 0.6054, 0.7274, 0.8067, 0.8573, 0.9216, and 0.9757. A vibrating tube densimeter was used to perform density measurements using two reference calibration fluids. The uncertainty is estimated to be better than {+-}0.2 kg . m{sup -3} for the experimental density measurements. For each mixture and for 1-pentanol, the experimental densities were correlated using an explicit volume equation of six parameters and an 11-parameter equation of state (EoS). Excess molar volumes were determined for the (CO{sub 2} + 1-pentanol) system using 1-pentanol densities calculated from the 11-parameter EoS and CO{sub 2} densities calculated from a multiparameter reference EoS.

  2. Congruences involving $\\binom{4k}{2k}$ and $\\binom{3k}k$

    OpenAIRE

    Sun, Zhi-Hong

    2011-01-01

    Let $p$ be a prime greater than 3. In the paper we mainly determine $\\sum_{k=0}^{[p/4]}\\binom{4k}{2k}(-1)^k$, $\\sum_{k=0}^{[p/3]}\\binom{3k}k, \\sum_{k=0}^{[p/3]}\\binom{3k}k(-1)^k$ and $\\sum_{k=0}^{[p/3]}\\binom{3k}k(-3)^k$ modulo $p$, where $[x]$ is the greatest integer not exceeding $x$.

  3. Thermodynamic study of phase equilibrium of superionic alloys of Ag3SBr1-xClx system in the concentration range 0.0-0.4 and temperature range 370-395 K

    Science.gov (United States)

    Moroz, M. V.; Prokhorenko, M. V.; Prokhorenko, S. V.; Reshetnyak, O. V.

    2017-03-01

    Thermodynamic assessment of the phase stability of the solid solutions of superionic alloys of the Ag3SBr1-xClx (I) system in the concentration range 0 ≤ x ≤ 0.4 and temperature range 370-395 K was performed. Partial functions of silver in the alloys of solid solution were used as the thermodynamic parameters. The values of partial thermodynamic functions were obtained with the use of the electromotive force method. Potential-forming processes were performed in electrochemical cells. Linear dependence of the electromotive force of cells on temperature was used to calculate the partial thermodynamic functions of silver in the alloys. The serpentine-like shape of the thermodynamic functions in the concentration range 0-4 is an evidence of the metastable state of solid solution. The equilibrium phase state of the alloys is predicted to feature the formation of the intermediate phase Ag3SBr0.76Cl0.24, and the solubility gap of the solid solution ranges of Ag3SBr0.76Cl0.24 and Ag3SBr.

  4. Metric of the 2–6 day sea-surface temperature response to wind stress in the Tropical Pacific and its sensitivity to the K-Profile Parameterization of vertical mixing

    KAUST Repository

    Wagman, Benjamin M.

    2014-05-04

    Uncertainty in wind forcing has long hampered direct tests of ocean model output against observations for the purpose of refining the boundary layer K-Profile Parameterization (KPP) of oceanic vertical mixing. Considered here is a short-term metric that could be sensitive to the ways in which the KPP directly affects the adjustment of sea surface temperatures for a given change in wind stress. In particular a metric is developed based on the lagged correlation between the 2–6 day filtered wind stress and sea surface temperature. The metric is normalized by estimated observational and model uncertainties such that the significance of differences may be assessed. For this purpose multiple wind reanalysis products and their blended combinations were used to represent the range of forcing uncertainty, while perturbed KPP parameter model runs explore the sensitivity of the metric to the parameterization of vertical mixing. The correlation metric is sensitive to perturbations to most KPP parameters, in ways that accord with expectations, although only a few parameters show a sensitivity on the same order as the sensitivity to switching between wind products. This suggests that uncertainties in wind forcing continue to be a significant limitation for applying direct observational tests of KPP physics. Moreover, model correlations are biased high, suggesting that the model lacks or does not resolve sources of variability on the 2–6 day time scale.

  5. K Balasubramanian

    Indian Academy of Sciences (India)

    Home; Journals; Bulletin of Materials Science. K Balasubramanian. Articles written in Bulletin of Materials Science. Volume 30 Issue 2 April 2007 pp 157-161 Mechno-chemical Synthesis. Application of mechano-chemical synthesis for protective coating on steel grinding media prior to ball milling of copper · Indranil Lahiri K ...

  6. Effect of sodium acetate on the volumetric behaviour of some mono-, di-, and tri-saccharides in aqueous solutions over temperature range (288.15 to 318.15) K

    Energy Technology Data Exchange (ETDEWEB)

    Banipal, Parampaul K., E-mail: pkbanipal@yahoo.co [Department of Chemistry, Guru Nanak Dev University, Amritsar 143 005 (India); Singh, Vickramjeet [Department of Chemistry, Guru Nanak Dev University, Amritsar 143 005 (India); Banipal, Tarlok S. [Department of Applied Chemistry, Guru Nanak Dev University, Amritsar 143 005 (India)

    2010-01-15

    The standard partial molar volumes, V{sub 2}{sup 0} at infinite dilution of eight monosaccharides [D(+)-xylose, D(-)-arabinose, D(-)-ribose, L(-)-sorbose, D(-)-fructose, D(+)-galactose, D(+)-glucose, and D(+)-mannose], six disaccharides [D(+)-cellobiose, sucrose, D(+)-melibiose, D(+)-lactose monohydrate, D(+)-trehalose dihydrate, and D(+)-maltose monohydrate] and two trisaccharides [D(+)-melizitose and D(+)-raffinose pentahydrate] (molalities of saccharides range from (0.03 to 0.12) mol . kg{sup -1}) have been determined in water and in (0.5, 1.0, 2.0, and 3.0) mol . kg{sup -1} aqueous sodium acetate solutions at temperatures, T = (288.15, 298.15, 308.15, and 318.15) K from density measurements using a vibrating-tube digital densimeter. From these results, corresponding standard partial molar volumes of transfer, DELTA{sub t}V{sub 2}{sup 0} have been determined for the transfer of various saccharides from water to aqueous solutions of sodium acetate. Positive values of DELTA{sub t}V{sub 2}{sup 0} were obtained for most of the saccharides, whose magnitude increase with the concentration of sodium acetate as well as temperature. However, negative DELTA{sub t}V{sub 2}{sup 0} values were observed for L(-)-sorbose, D(-)-fructose and D(+)-xylose at lower concentrations of co-solute. The negative magnitude of DELTA{sub t}V{sub 2}{sup 0} values decrease with rise of temperature from (288.15 to 318.15) K. Pair and higher order volumetric interaction coefficients have been determined by using McMillan-Mayer theory. Partial molar expansion coefficients, (partial derivV{sub 2}{sup 0}/partial derivT){sub p} and the second derivatives (partial deriv{sup 2}V{sub 2}{sup 0}/partial derivT{sup 2}){sub p} have also been estimated. These parameters have been utilized to understand various mixing effects in aqueous solutions due to the interactions between solute (saccharide) and co-solute (sodium acetate).

  7. Speeds of sound in {l_brace}(1 - x)CH{sub 4} + xN{sub 2}{r_brace} with x = (0.10001, 0.19999, and 0.5422) at temperatures between 170 K and 400 K and pressures up to 30 MPa

    Energy Technology Data Exchange (ETDEWEB)

    Estela-Uribe, J.F. [Facultad de Ingenieria, Universidad Javeriana-Cali, Calle 18, 118-250 Cali (Colombia); Trusler, J.P.M. [Department of Chemical Engineering, Imperial College London, London SW7 2AZ (United Kingdom)]. E-mail: m.trusler@imperial.ac.uk; Chamorro, C.R. [Grupo de Termodinamica y Calibracion (TERMOCAL), Dpto. Ingenieria Energetica y Fluidomecanica, E.T.S. de Ingenieros Industriales, Universidad de Valladolid, E-47071 Valladolid (Spain); Segovia, J.J. [Grupo de Termodinamica y Calibracion (TERMOCAL), Dpto. Ingenieria Energetica y Fluidomecanica, E.T.S. de Ingenieros Industriales, Universidad de Valladolid, E-47071 Valladolid (Spain); Martin, M.C. [Grupo de Termodinamica y Calibracion (TERMOCAL), Dpto. Ingenieria Energetica y Fluidomecanica, E.T.S. de Ingenieros Industriales, Universidad de Valladolid, E-47071 Valladolid (Spain); Villamanan, M.A. [Grupo de Termodinamica y Calibracion (TERMOCAL), Dpto. Ingenieria Energetica y Fluidomecanica, E.T.S. de Ingenieros Industriales, Universidad de Valladolid, E-47071 Valladolid (Spain)

    2006-07-15

    The speed of sound in {l_brace}(1 - x)CH{sub 4} + xN{sub 2}{r_brace} has been measured with a spherical acoustic resonator. Two mixtures with x = (0.10001 and 0.19999) were studied along isotherms at temperatures between 220 K and 400 K with pressures up to 20 MPa; a few additional measurements at p = (25 and 30) MPa are also reported. A third mixture with x = 0.5422 was studied along pseudo-isochores at amount-of-substance densities between 0.2 mol . dm{sup -3} and 5 mol . dm{sup -3}. Corrections for molecular vibrational relaxation are discussed in detail and relaxation times are reported. The overall uncertainty of the measured speeds of sound is estimated to be not worse than {+-}0.02%, except for those measurements in the mixture with x = 0.5422 that lie along the pseduo-isochore at the highest amount-of-substance density. The results have been compared with the predictions of several equations of state used for natural gas systems.

  8. High-temperature behaviour of astrophyllite, K2NaFe7 2+Ti2(Si4O12)2O2(OH)4F: a combined X-ray diffraction and Mössbauer spectroscopic study

    Science.gov (United States)

    Zhitova, Elena S.; Krivovichev, Sergey V.; Hawthorne, Frank C.; Krzhizhanovskaya, Maria G.; Zolotarev, Andrey A.; Abdu, Yassir A.; Yakovenchuk, Viktor N.; Pakhomovsky, Yakov A.; Goncharov, Alexey G.

    2017-09-01

    High-temperature X-ray powder-diffraction study of astrophyllite, K2NaFe7 2+Ti2(Si4O12)2O2(OH)4F, and investigation of the samples annealed at 600 and 700 °C, reveal the occurrence of a phase transformation due to the thermal iron oxidation coupled with (1) deprotonation according to the scheme Fe2+ + OH- → Fe3+ + O2- + ½H2 ↑, and (2) defluorination according to the scheme Fe2+ + F- → Fe3+ + O2-. The phase transformation occurs at 500 °C, it is irreversible and without symmetry changes. The mineral decomposes at 775 °C. Both astrophyllite and its high-temperature dehydroxylated (HT) modification are triclinic, P-1. The unit-cell parameters are a = 5.3752(1), b = 11.8956(3), c = 11.6554(3) Å, α = 113.157(3), β = 94.531(2), γ = 103.112(2)º, V = 655.47(3) Å3 for unheated astrophyllite, and a = 5.3287(4), b = 11.790(1), c = 11.4332(9) Å, α = 112.530(8), β = 94.539(6), γ = 103.683(7)º, V = 633.01(9) Å3 for the HT (annealed) modification of astrophyllite. The oxidation of iron is confirmed: (1) by the presence of an exothermic effect at 584 °C in the DTA/TG curves in an Ar-O atmosphere and its absence in an Ar-Ar atmosphere and (2) by ex situ Mössbauer spectroscopy that showed the oxidation of Fe2+ to Fe3+ in the samples heated to 700 °C. Deprotonation was detected by the evolution of IR spectra in the region 3600-3000 cm-1 for astrophyllite and its HT modification. Defluorination was detected by the presence of F in the electron microprobe analysis of unheated astrophyllite and the absence of F in the analysis of unpolished heated astrophyllite. The significant difference between astrophyllite and its HT modification is in the reduction of the M-O interatomic distances after heating to 500 °C and the distortion indices of the MO6 and Dφ6 octahedra. Thermal behaviour of astrophyllite in the 25-475 °C temperature range can be described as a volume thermal expansion with maximal coefficient of thermal expansion in the direction perpendicular to

  9. HCl yield and chemical kinetics study of the reaction of Cl atoms with CH3I at the 298 K temperature using the infra-red tunable diode laser absorption spectroscopy

    Science.gov (United States)

    Sharma, R. C.; Blitz, M.; Wada, R.; Seakins, P. W.

    2014-07-01

    Pulsed ArF excimer laser (193 nm) - CW infrared(IR) tunable diode laser Herriott type absorption spectroscopic technique has been made for the detection of product hydrochloric acid HCl. Absorption spectroscopic technique is used in the reaction chlorine atoms with methyl iodide (Cl + CH3I) to the study of kinetics on reaction Cl + CH3I and the yield of (HCl). The reaction of Cl + CH3I has been studied with the support of the reaction Cl + C4H10 (100% HCl) at temperature 298 K. In the reaction Cl + CH3I, the total pressure of He between 20 and 125 Torr at the constant concentration of [CH3I] 7.0 × 1014 molecule cm-3. In the present work, we estimated adduct formation is very important in the reaction Cl + CH3I and reversible processes as well and CH3I molecule photo-dissociated in the methyl [CH3] radical. The secondary chemistry has been studied as CH3 + CH3ICl = product, and CH3I + CH3ICl = product2. The system has been modeled theoretically for secondary chemistry in the present work. The calculated and experimentally HCl yield nearly 65% at the concentration 1.00 × 1014 molecule cm-3 of [CH3I] and 24% at the concentration 4.0 × 1015 molecule cm-3 of [CH3I], at constant concentration 4.85 × 1012 molecule cm-3 of [CH3], and at 7.3 × 1012 molecule cm-3 of [Cl]. The pressure dependent also studied product of HCl at the constant [CH3], [Cl] and [CH3I]. The experimental results are also very good matching with the modelling work at the reaction CH3 + CH3ICl = product (k = (2.75 ± 0.35) × 10-10 s-1) and CH3I + CH3ICl = product2 (k = 1.90 ± 0.15) × 10-12 s-1. The rate coefficients of the reaction CH3 + CH3ICl and CH3I + CH3ICl has been made in the present work. The experimental results has been studied by two method (1) phase locked and (2) burst mode.

  10. HCl yield and chemical kinetics study of the reaction of Cl atoms with CH3I at the 298K temperature using the infra-red tunable diode laser absorption spectroscopy.

    Science.gov (United States)

    Sharma, R C; Blitz, M; Wada, R; Seakins, P W

    2014-07-15

    Pulsed ArF excimer laser (193 nm)-CW infrared (IR) tunable diode laser Herriott type absorption spectroscopic technique has been made for the detection of product hydrochloric acid HCl. Absorption spectroscopic technique is used in the reaction chlorine atoms with methyl iodide (Cl+CH3I) to the study of kinetics on reaction Cl+CH3I and the yield of (HCl). The reaction of Cl+CH3I has been studied with the support of the reaction Cl+C4H10 (100% HCl) at temperature 298 K. In the reaction Cl+CH3I, the total pressure of He between 20 and 125 Torr at the constant concentration of [CH3I] 7.0×10(14) molecule cm(-3). In the present work, we estimated adduct formation is very important in the reaction Cl+CH3I and reversible processes as well and CH3I molecule photo-dissociated in the methyl [CH3] radical. The secondary chemistry has been studied as CH3+CH3ICl = product, and CH3I+CH3ICl = product2. The system has been modeled theoretically for secondary chemistry in the present work. The calculated and experimentally HCl yield nearly 65% at the concentration 1.00×10(14) molecule cm(-3) of [CH3I] and 24% at the concentration 4.0×10(15) molecule cm(-3) of [CH3I], at constant concentration 4.85×10(12) molecule cm(-3) of [CH3], and at 7.3×10(12) molecule cm(-3) of [Cl]. The pressure dependent also studied product of HCl at the constant [CH3], [Cl] and [CH3I]. The experimental results are also very good matching with the modelling work at the reaction CH3+CH3ICl = product (k = (2.75±0.35)×10(-10) s(-1)) and CH3I+CH3ICl = product2 (k = 1.90±0.15)×10(-12) s(-1). The rate coefficients of the reaction CH3+CH3ICl and CH3I+CH3ICl has been made in the present work. The experimental results has been studied by two method (1) phase locked and (2) burst mode. Copyright © 2014 Elsevier B.V. All rights reserved.

  11. Rescaling Temperature and Entropy

    Science.gov (United States)

    Olmsted, John, III

    2010-01-01

    Temperature and entropy traditionally are expressed in units of kelvin and joule/kelvin. These units obscure some important aspects of the natures of these thermodynamic quantities. Defining a rescaled temperature using the Boltzmann constant, T' = k[subscript B]T, expresses temperature in energy units, thereby emphasizing the close relationship…

  12. The early stages of growth of Mn deposited at room temperature on Ag (001) studied by Mn K-edge SEXAFS and Mn L/sub 2/, L/sub 3/-edges XAS

    CERN Document Server

    Schieffer, P; Krembel, C; Hanf, M C; Gewinner, G; Chandesris, D; Magnan, H; Hricovini, K

    1999-01-01

    The atomic structure of the Ag/sub 0.5/Mn/sub 0.5/ ordered surface alloy formed in the two topmost layers of the Ag substrate when 1 monolayer (ML) Mn is deposited at room temperature on Ag(001) is determined by using Mn K-edge surface extended X-ray absorption fine structure (SEXAFS). The results, which are in agreement with the c (2*2) low energy electron diffraction (LEED) pattern and X-ray photoelectron diffraction (XPD), establishes that Mn adopts here an unusually large atomic volume which is consistent with a large atomic-like moment. The Mn L/sub 2/L/sub 3/ edges soft X-ray absorption spectroscopy (XAS) study of 1ML Mn in-situ deposited confirms that Mn adopts a stable high spin state. For thicker deposits, the growth of a body-centered tetragonal lattice of pure Mn on this diffuse interface is confirmed. (14 refs).

  13. Superconductivity at 28 K in RbxC60

    NARCIS (Netherlands)

    Rosseinsky, M.J.; Ramirez, A.P.; Glarum, S.H.; Murphy, D.W.; Haddon, R.C.; Hebard, A.F.; Palstra, T.T.M.; Kartan, A.R.; Zahurak, S.M.; Makhija, A.V.

    1991-01-01

    Meissner-effect and microwave-absorption measurements on bulk samples show that RbxC60 is superconducting with a maximum transition temperature of 28 K. This is a 10-K (60%) increase over the K-doped material. Only Ba0.6K0.4BiO3 and the cuprate superconductors have higher transition temperatures.

  14. Colourings of (k-r,k-trees

    Directory of Open Access Journals (Sweden)

    M. Borowiecki

    2017-01-01

    Full Text Available Trees are generalized to a special kind of higher dimensional complexes known as \\((j,k\\-trees ([L. W. Beineke, R. E. Pippert, On the structure of \\((m,n\\-trees, Proc. 8th S-E Conf. Combinatorics, Graph Theory and Computing, 1977, 75-80], and which are a natural extension of \\(k\\-trees for \\(j=k-1\\. The aim of this paper is to study\\((k-r,k\\-trees ([H. P. Patil, Studies on \\(k\\-trees and some related topics, PhD Thesis, University of Warsaw, Poland, 1984], which are a generalization of \\(k\\-trees (or usual trees when \\(k=1\\. We obtain the chromatic polynomial of \\((k-r,k\\-trees and show that any two \\((k-r,k\\-trees of the same order are chromatically equivalent. However, if \\(r\

  15. Kinetics of the gas-phase reactions of chlorine atoms with CH2F2, CH3CCl3 and CF3CFH2 over the temperature range 253 – 551 K

    DEFF Research Database (Denmark)

    Nilsson, Elna Johanna Kristina; Johnson, Matthew Stanley; Nielsen, Ole John

    2009-01-01

    Relative rate techniques were used to study the title reactions in 930–1200 mbar of N2 diluent. The reaction rate coefficients measured in the present work are summarized by the expressions k(Cl+CH2F2) = 1.19×10-17 T 2 exp(-1023/T ) cm3 molecule-1 s-1 (253– 553 K), k(Cl+CH3CCl3) = 2.41×10-12 exp(...

  16. Radiolysis of Potassium Picrate in 77 K

    Science.gov (United States)

    Yakubik, D. G.; Pak, V. Kh; Anan'ev, V. A.; Ghyngazov, S. A.

    2016-02-01

    The formation of paramagnetic centers in potassium picrate under irradiation at low temperature was investigated. The heating irradiated at 77 K potassium picrate crystal to room temperature results in paramagnetic centers - 2,6-dinitro-para-quinone radicals, ortho- and para-iminoxyl radicals and atomic oxygen. These products are formed under irradiation at room temperature.

  17. Development of a highly efficient conversion electron Moessbauer spectroscopy (CEMS) detector for low temperature (<20 K) measurements and tests on Fe / (Eu{sub x}Pb{sub 1-x})Te bilayers; Desenvolvimento de um detector de alta eficiencia para espectroscopia Moessbauer de eletrons de conversao (CEMS) a baixas temperaturas (<20K) e testes em bicamadas Fe / (Eu{sub x}Pb{sub 1-x})Te

    Energy Technology Data Exchange (ETDEWEB)

    Pombo, Carlos Jose da Silva Matos

    2006-07-01

    The {sup 57}Fe Moessbauer spectroscopy is a nuclear, non-destructive technique used for the investigation of structural, magnetic and hyperfine properties of several materials. It is a powerful tool in characterizing materials in physics, metallurgy, geology and biology field areas, especially magnetic materials, alloys and minerals containing Fe. Lately, the Conversion Electron Moessbauer Spectroscopy (CEMS) is widely used in making studies on ultra-thin magnetic films, as well as other nanostructured materials. In case of magnetic nanostructures, low temperature (LT) studies are especially important due to the possibility of dealing with superparamagnetic effects. In this work it was developed a CEMS measurement system for low temperatures (<20 K) based on a solid-state electron multiplier (Channeltron{sup R}) and an optical cryostat (Model SVT-400, Janis Research Co, USA), from which the project was originally conceived at the Applied Physics / Moessbauer spectroscopy Department from University of Duisburg-Essen, Germany. The LT-CEMS system was fully built, tested and successfully applied in a preliminary characterization of Fe/(Eu{sub x}Pb{sub 1-x})Te(111) bilayers with use of a 15 angstrom, {sup 57} Fe probe layer, with reasonable results at sample temperatures as low as 8 K. (author)

  18. Branching Fraction Measurements of Charged B Decays to K*+K+K-, K*+pi+K-, K*+K+pi- and K*+pi+pi- Final States

    CERN Document Server

    Aubert, B; Bóna, M; Boutigny, D; Couderc, F; Karyotakis, Yu; Lees, J P; Poireau, V; Tisserand, V; Zghiche, A; Graugès-Pous, E; Palano, A; Chen, J C; Qi, N D; Rong, G; Wang, P; Zhu, Y S; Eigen, G; Ofte, I; Stugu, B; Abrams, G S; Battaglia, M; Brown, D N; Button-Shafer, J; Cahn, R N; Charles, E; Gill, M S; Groysman, Y; Jacobsen, R G; Kadyk, J A; Kerth, L T; Kolomensky, Yu G; Kukartsev, G; Lynch, G; Mir, L M; Orimoto, T J; Pripstein, M; Roe, N A; Ronan, M T; Wenzel, W A; Del Amo-Sánchez, P; Barrett, M; Ford, K E; Harrison, T J; Hart, A J; Hawkes, C M; Morgan, S E; Watson, A T; Held, T; Koch, H; Lewandowski, B; Pelizaeus, M; Peters, K; Schröder, T; Steinke, M; Boyd, J T; Burke, J P; Cottingham, W N; Walker, D; Çuhadar-Dönszelmann, T; Fulsom, B G; Hearty, C; Knecht, N S; Mattison, T S; McKenna, J A; Khan, A; Kyberd, P; Saleem, M; Sherwood, D J; Teodorescu, L; Blinov, V E; Bukin, A D; Druzhinin, V P; Golubev, V B; Onuchin, A P; Serednyakov, S I; Skovpen, Yu I; Solodov, E P; Todyshev, K Yu; Best, D S; Bondioli, M; Bruinsma, M; Chao, M; Curry, S; Eschrich, I; Kirkby, D; Lankford, A J; Lund, P; Mandelkern, M A; Mommsen, R K; Röthel, W; Stoker, D P; Abachi, S; Buchanan, C; Foulkes, S D; Gary, J W; Long, O; Shen, B C; Wang, K; Zhang, L; Hadavand, H K; Hill, E J; Paar, H P; Rahatlou, S; Sharma, V; Berryhill, J W; Campagnari, C; Cunha, A; Dahmes, B; Hong, T M; Kovalskyi, D; Richman, J D; Beck, T W; Eisner, A M; Flacco, C J; Heusch, C A; Kroseberg, J; Lockman, W S; Nesom, G; Schalk, T; Schumm, B A; Seiden, A; Spradlin, P; Williams, D C; Wilson, M G; Albert, J; Chen, E; Dvoretskii, A; Fang, F; Hitlin, D G; Narsky, I; Piatenko, T; Porter, F C; Ryd, A; Samuel, A; Mancinelli, G; Meadows, B T; Mishra, K; Sokoloff, M D; Blanc, F; Bloom, P C; Chen, S; Ford, W T; Hirschauer, J F; Kreisel, A; Nagel, M; Nauenberg, U; Olivas, A; Ruddick, W O; Smith, J G; Ulmer, K A; Wagner, S R; Zhang, J; Chen, A; Eckhart, E A; Soffer, A; Toki, W H; Wilson, R J; Winklmeier, F; Zeng, Q; Altenburg, D D; Feltresi, E; Hauke, A; Jasper, H; Petzold, A; Spaan, B; Brandt, T; Klose, V; Lacker, H M; Mader, W F; Nogowski, R; Schubert, J; Schubert, K R; Schwierz, R; Sundermann, J E; Volk, A; Bernard, D; Bonneaud, G R; Grenier, P; Latour, E; Thiebaux, C; Verderi, M; Clark, P J; Gradl, W; Muheim, F; Playfer, S; Robertson, A I; Xie, Y; Andreotti, M; Bettoni, D; Bozzi, C; Calabrese, R; Cibinetto, G; Luppi, E; Negrini, M; Petrella, A; Piemontese, L; Prencipe, E; Anulli, F; Baldini-Ferroli, R; Calcaterra, A; De Sangro, R; Finocchiaro, G; Pacetti, S; Patteri, P; Peruzzi, I M; Piccolo, M; Rama, M; Zallo, A; Buzzo, A; Capra, R; Contri, R; Lo Vetere, M; Macri, M M; Monge, M R; Passaggio, S; Patrignani, C; Robutti, E; Santroni, A; Tosi, S; Brandenburg, G; Chaisanguanthum, K S; Morii, M; Wu, J; Dubitzky, R S; Marks, J; Schenk, S; Uwer, U; Bhimji, W; Bowerman, D A; Dauncey, P D; Egede, U; Flack, R L; Nash, J A; Nikolich, M B; Panduro-Vazquez, W; Behera, P K; Chai, X; Charles, M J; Mallik, U; Meyer, N T; Ziegler, V; Cochran, J; Crawley, H B; Dong, L; Eyges, V; Meyer, W T; Prell, S; Rosenberg, E I; Rubin, A E; Gritsan, A V; Denig, A G; Fritsch, M; Schott, G; Arnaud, N; Davier, M; Grosdidier, G; Höcker, A; Le Diberder, F R; Lepeltier, V; Lutz, A M; Oyanguren, A; Pruvot, S; Rodier, S; Roudeau, P; Schune, M H; Stocchi, A; Wang, W F; Wormser, G; Cheng, C H; Lange, D J; Wright, D M; Chavez, C A; Forster, I J; Fry, J R; Gabathuler, E; Gamet, R; George, K A; Hutchcroft, D E; Payne, D J; Schofield, K C; Touramanis, C; Bevan, A J; Di Lodovico, F; Menges, W; Sacco, R; Cowan, G; Flächer, H U; Hopkins, D A; Jackson, P S; McMahon, T R; Ricciardi, S; Salvatore, F; Wren, A C; Davis, C L; Allison, J; Barlow, N R; Barlow, R J; Chia, Y M; Edgar, C L; Lafferty, G D; Naisbit, M T; Williams, J C; Yi, J I; Chen, C; Hulsbergen, W D; Jawahery, A; Lae, C K; Roberts, D A; Simi, G; Blaylock, G; Dallapiccola, C; Hertzbach, S S; Li, X; Moore, T B; Saremi, S; Stängle, H; Cowan, R; Sciolla, G; Sekula, S J; Spitznagel, M; Taylor, F; Yamamoto, R K; Kim, H; Mclachlin, S E; Patel, P M; Robertson, S H; Lazzaro, A; Lombardo, V; Palombo, F; Bauer, J M; Cremaldi, L; Eschenburg, V; Godang, R; Kroeger, R; Sanders, D A; Summers, D J; Zhao, H W; Brunet, S; Côté, D; Simard, M; Taras, P; Viaud, F B; Nicholson, H; Cavallo, N; De Nardo, Gallieno; Fabozzi, F; Gatto, C; Lista, L; Monorchio, D; Paolucci, P; Piccolo, D; Sciacca, C; Baak, M; Raven, G; Snoek, H L; Jessop, C P; LoSecco, J M; Allmendinger, T; Benelli, G; Gan, K K; Honscheid, K; Hufnagel, D; Jackson, P D; Kagan, H; Kass, R; Rahimi, A M; Ter-Antonian, R; Wong, Q K; Blount, N L; Brau, J E; Frey, R; Igonkina, O; Lu, M; Rahmat, R; Sinev, N B; Strom, D; Strube, J; Torrence, E; Gaz, A; Margoni, M; Morandin, M; Pompili, A; Posocco, M; Rotondo, M; Simonetto, F; Stroili, R; Voci, C; Benayoun, M; Chauveau, J; Briand, H; David, P; Del Buono, L; La Vaissière, C de; Hamon, O; Hartfiel, B L; John, M J J; Leruste, P; Malcles, J; Ocariz, J; Roos, L; Therin, G; Gladney, L; Panetta, J; Biasini, M; Covarelli, R; Angelini, C; Batignani, G; Bettarini, S; Bucci, F; Calderini, G; Carpinelli, M; Cenci, R; Forti, F; Giorgi, M A; Lusiani, A; Marchiori, G; Mazur, M A; Morganti, M; Neri, N; Rizzo, G; Walsh, J J; Haire, M; Judd, D; Wagoner, D E; Biesiada, J; Danielson, N; Elmer, P; Lau, Y P; Lü, C; Olsen, J; Smith, A J S; Telnov, A V; Bellini, F; Cavoto, G; D'Orazio, A; Del Re, D; Di Marco, E; Faccini, R; Ferrarotto, F; Ferroni, F; Gaspero, M; Li Gioi, L; Mazzoni, M A; Morganti, S; Piredda, G; Polci, F; Safai-Tehrani, F; Voena, C; Ebert, M; Schröder, H; Waldi, R; Adye, T; De, N; Groot; Franek, B; Olaiya, E O; Wilson, F F; Aleksan, R; Emery, S; Gaidot, A; Ganzhur, S F; Hamel de Monchenault, G; Kozanecki, Witold; Legendre, M; Vasseur, G; Yéche, C; Zito, M; Chen, X R; Liu, H; Park, W; Purohit, M V; Wilson, J R; Allen, M T; Aston, D; Bartoldus, R; Bechtle, P; Berger, N; Claus, R; Coleman, J P; Convery, M R; Cristinziani, M; Dingfelder, J C; Dorfan, J; Dubois-Felsmann, G P; Dujmic, D; Dunwoodie, W M; Field, R C; Glanzman, T; Gowdy, S J; Graham, M T; Halyo, V; Hast, C; Hrynóva, T; Innes, W R; Kelsey, M H; Kim, P; Leith, D W G S; Li, S; Luitz, S; Lüth, V; Lynch, H L; MacFarlane, D B; Marsiske, H; Messner, R; Müller, D R; O'Grady, C P; Ozcan, V E; Perazzo, A; Perl, M; Pulliam, T; Ratcliff, B N; Roodman, A; Salnikov, A A; Schindler, R H; Schwiening, J; Snyder, A; Stelzer, J; Su, D; Sullivan, M K; Suzuki, K; Swain, S K; Thompson, J M; Vavra, J; Van Bakel, N; Weaver, M; Weinstein, A J R; Wisniewski, W J; Wittgen, M; Wright, D H; Yarritu, A K; Yi, K; Young, C C; Burchat, P R; Edwards, A J; Majewski, S A; Petersen, B A; Roat, C; Wilden, L; Ahmed, S; Alam, M S; Bula, R; Ernst, J A; Jain, V; Pan, B; Saeed, M A; Wappler, F R; Zain, S B; Bugg, W; Krishnamurthy, M; Spanier, S M; Eckmann, R; Ritchie, J L; Satpathy, A; Schilling, C J; Schwitters, R F; Izen, J M; Lou, X C; Ye, S; Bianchi, F; Gallo, F; Gamba, D; Bomben, M; Bosisio, L; Cartaro, C; Cossutti, F; Della Ricca, G; Dittongo, S; Lanceri, L; Vitale, L; Azzolini, V; Martínez-Vidal, F; Banerjee, Sw; Bhuyan, B; Brown, C M; Fortin, D; Hamano, K; Kowalewski, R V; Nugent, I M; Roney, J M; Sobie, R J; Back, J J; Harrison, P F; Latham, T E; Mohanty, G B; Pappagallo, M; Band, H R; Chen, X; Cheng, B; Dasu, S; Datta, M; Flood, K T; Hollar, J J; Kutter, P E; Mellado, B; Mihályi, A; Pan, Y; Pierini, M; Prepost, R; Wu, S L; Yu, Z; Neal, H; al, et

    2006-01-01

    Branching fraction and asymmetry measurements of charmless $B^+\\to K^{*+}h^+_1h^-_2$ (where $h_{1,2}$ = $K$, $\\pi$) decays are presented, using a data sample of 232 million $\\Upsilon(4S) \\to$ $BB$ decays collected with the BaBar detector at the SLAC PEP-II asymmetric-energy $B$ factory. Using a maximum likelihood fit, the following branching fraction results were obtained: ${\\cal B}$($B^+ \\to K^{*+}K^+ K^-)$ = (36.2 $\\pm$ 3.3 $\\pm$ 3.6) $\\times$ 10$^{-6}$ and ${\\cal B}$($B^+$ $\\to$ $K^{*+}\\pi^+\\pi^-$) = (75.3 $\\pm$ 6.0 $\\pm$ 8.1) $\\times$ 10$^{-6}$. Upper limits were set for ${\\cal B}$($B^+$ $\\to$ $K^{*+}\\pi^+ K^-$) $<$ 11.8 $\\times$ 10$^{-6}$ and ${\\cal B}$($B^+$ $\\to$ $K^{*+}K^+ \\pi^-$) $<$ 6.1 $\\times$ 10$^{-6}$ at 90% confidence level. The charge asymmetries for the decays $B^+ \\to K^{*+}K^+ K^-$ and $B^+$ $\\to$ $K^{*+}\\pi^+\\pi^-$ were measured to be ${\\cal A}_{K^*KK} = 0.11 \\pm 0.08 \\pm 0.03$ and ${\\cal A}_{K^*\\pi\\pi} = 0.07 \\pm 0.07 \\pm 0.04$, respectively. The first error quoted on branching frac...

  19. Low-temperature high magnetic field powder x-ray diffraction setup for field-induced structural phase transition studies from 2 to 300 K and at 0 to 8-T field

    Science.gov (United States)

    Shahee, Aga; Sharma, Shivani; Kumar, Dhirendra; Yadav, Poonam; Bhardwaj, Preeti; Ghodke, Nandkishor; Singh, Kiran; Lalla, N. P.; Chaddah, P.

    2016-10-01

    A low-temperature and high magnetic field powder x-ray diffractometer (XRD) has been developed at UGC-DAE CSR (UGC: University Grant Commission, DAE: Department of Atomic Energy, and CSR: Consortium for scientific research), Indore, India. The setup has been developed around an 18 kW rotating anode x-ray source delivering Cu-Kα x-rays coming from a vertical line source. It works in a symmetric θ-2θ parallel beam geometry. It consists of a liquid helium cryostat with an 8 T split-pair Nb-Ti superconducting magnet comprising two x-ray windows each covering an angular range of 65°. This is mounted on a non-magnetic type heavy duty goniometer equipped with all necessary motions along with data collection accessories. The incident x-ray beam has been made parallel using a parabolic multilayer mirror. The scattered x-ray is detected using a NaI detector through a 0.1° acceptance solar collimator. To control the motions of the goniometer, a computer programme has been developed. The wide-angle scattering data can be collected in a range of 2°-115° of 2θ with a resolution of ˜0.1°. The whole setup is tightly shielded for the scattered x-rays using a lead hutch. The functioning of the goniometer and the artifacts arising possibly due to the effect of stray magnetic field on the goniometer motions, on the x-ray source, and on the detector have been characterized by collecting powder XRD data of a National Institute of Standards and Technology certified standard reference material LaB6 (SRM-660b) and Si powder in zero-field and in-field conditions. Occurrence of field induced structural-phase transitions has been demonstrated on various samples like Pr0.5Sr0.5MnO3, Nd0.49Sr0.51MnO3-δ and La0.175Pr0.45Ca0.375MnO3 by collecting data in zero field cool and field cool conditions.

  20. Low-temperature high magnetic field powder x-ray diffraction setup for field-induced structural phase transition studies from 2 to 300 K and at 0 to 8-T field.

    Science.gov (United States)

    Shahee, Aga; Sharma, Shivani; Kumar, Dhirendra; Yadav, Poonam; Bhardwaj, Preeti; Ghodke, Nandkishor; Singh, Kiran; Lalla, N P; Chaddah, P

    2016-10-01

    A low-temperature and high magnetic field powder x-ray diffractometer (XRD) has been developed at UGC-DAE CSR (UGC: University Grant Commission, DAE: Department of Atomic Energy, and CSR: Consortium for scientific research), Indore, India. The setup has been developed around an 18 kW rotating anode x-ray source delivering Cu-Kα x-rays coming from a vertical line source. It works in a symmetric θ-2θ parallel beam geometry. It consists of a liquid helium cryostat with an 8 T split-pair Nb-Ti superconducting magnet comprising two x-ray windows each covering an angular range of 65°. This is mounted on a non-magnetic type heavy duty goniometer equipped with all necessary motions along with data collection accessories. The incident x-ray beam has been made parallel using a parabolic multilayer mirror. The scattered x-ray is detected using a NaI detector through a 0.1° acceptance solar collimator. To control the motions of the goniometer, a computer programme has been developed. The wide-angle scattering data can be collected in a range of 2°-115° of 2θ with a resolution of ∼0.1°. The whole setup is tightly shielded for the scattered x-rays using a lead hutch. The functioning of the goniometer and the artifacts arising possibly due to the effect of stray magnetic field on the goniometer motions, on the x-ray source, and on the detector have been characterized by collecting powder XRD data of a National Institute of Standards and Technology certified standard reference material LaB6 (SRM-660b) and Si powder in zero-field and in-field conditions. Occurrence of field induced structural-phase transitions has been demonstrated on various samples like Pr0.5Sr0.5MnO3, Nd0.49Sr0.51MnO3-δ and La0.175Pr0.45Ca0.375MnO3 by collecting data in zero field cool and field cool conditions.

  1. Summary of ISNP2K

    Indian Academy of Sciences (India)

    Abstract. This is a brief summary of the ISNP2K (International Symposium on Nuclear Physics,. 2000). Many interesting works were presented on new developments and perspectives of nuclear physics in the plenary and poster sessions. Subjects discussed are 1) high temperature and high density nuclei, new QGP phases ...

  2. Water types and their relaxation behavior in partially rehydrated CaFe-mixed binary oxide obtained from CaFe-layered double hydroxide in the 155-298 K temperature range.

    Science.gov (United States)

    Bugris, Valéria; Haspel, Henrik; Kukovecz, Ákos; Kónya, Zoltán; Sipiczki, Mónika; Sipos, Pál; Pálinkó, István

    2013-10-29

    Heat-treated CaFe-layered double hydroxide samples were equilibrated under conditions of various relative humidities (11%, 43% and 75%). Measurements by FT-IR and dielectric relaxation spectroscopies revealed that partial to full reconstruction of the layered structure took place. Water types taking part in the reconstruction process were identified via dielectric relaxation measurements either at 298 K or on the flash-cooled (to 155 K) samples. The dynamics of water molecules at the various positions was also studied by this method, allowing the flash-cooled samples to warm up to 298 K.

  3. P K Bose

    Indian Academy of Sciences (India)

    Home; Journals; Bulletin of Materials Science. P K Bose. Articles written in Bulletin of Materials Science. Volume 26 Issue 4 June 2003 pp 365-369 Thin Films. Electrical properties of Ta2O5 films deposited on ZnO · S K Nandi S Chatterjee S K Samanta G K Dalapati P K Bose S Varma Shivprasad Patil C K Maiti.

  4. P K Dey

    Indian Academy of Sciences (India)

    Home; Journals; Sadhana. P K Dey. Articles written in Sadhana. Volume 31 Issue 5 October 2006 pp 583-595. Analytical model for erosion behaviour of impacted fly-ash particles on coal-fired boiler components · S K Das K M Godiwalla S P Mehrotra K K M Sastry P K Dey · More Details Abstract Fulltext PDF.

  5. P K Vijayan

    Indian Academy of Sciences (India)

    Home; Journals; Sadhana. P K Vijayan. Articles written in Sadhana. Volume 38 Issue 5 October 2013 pp 925-943. Safety features in nuclear power plants to eliminate the need of emergency planning in public domain · P K Vijayan M T Kamble A K Nayak K K Vaze R K Sinha · More Details Abstract Fulltext PDF. Following ...

  6. High cycle fatigue properties of CLAM steel at 723 K and 823 K

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Yanyun; Zhai, Xiangwei; Liu, Shaojun, E-mail: shaojun.liu@fds.org.cn; Li, Chunjing; Huang, Qunying

    2015-11-15

    Highlights: • High cycle fatigue properties of CLAM steel were investigated at 723 K and 823 K. • The condition fatigue limit at N = 10{sup 7} were 275 MPa and 235 MPa at 723 K and 823 K. • Fatigue strength decreased when stress and temperature increased at 723 K and 823 K. • Dislocation density decrease and subgrain coarsening during the test process were the possible reasons for fatigue limit decrease. - Abstract: This paper highlights the results of a study on the high cycle fatigue strength and fracture mechanism of China Low Activation Martensitic (CLAM) steel. The high cycle fatigue test results showed that the fatigue strength of CLAM steel decreased with the temperature, and the condition fatigue strengths (N = 10{sup 7}) were 275 MPa and 235 MPa at 723 K and 823 K, respectively. The fractograph results indicated that the fractures were mainly initiated from the surface of the specimen.

  7. P K Jain

    Indian Academy of Sciences (India)

    Home; Journals; Sadhana. P K Jain. Articles written in Sadhana. Volume 38 Issue 6 December 2013 pp 1347-1356. Cold test of cylindrical open resonator for 42 GHz, 200 kW gyrotron · Vivek Yadav Sudeep Sharan Hasina Khatun Nitin Kumar M K Alaria B Jha S C Deorani A K Sinha P K Jain · More Details Abstract Fulltext ...

  8. K Karunakaran Nair

    Indian Academy of Sciences (India)

    Home; Journals; Pramana – Journal of Physics. K Karunakaran Nair. Articles written in Pramana – Journal of Physics. Volume 67 Issue 3 September 2006 pp 501-506 Research Articles. Simulated mixed absorbers and effective atomic numbers for attenuation · K Karunakaran Nair N Ramachandran K K Abdullah K M ...

  9. Dalitz Analysis of Ds -> K K- pi-

    Energy Technology Data Exchange (ETDEWEB)

    del Amo Sanchez, P.; Lees, J.P.; Poireau, V.; Prencipe, E.; Tisserand, V.; /Annecy, LAPP; Garra Tico, J.; Grauges, E.; /Barcelona U., ECM; Martinelli, M.; Milanes, D.A.; Palano, A.; Pappagallo, M.; /INFN, Bari /Bari U.; Eigen, G.; Stugu, B.; Sun, L.; /Bergen U.; Brown, D.N.; Kerth, L.T.; Kolomensky, Yu.G.; Lynch, G.; Osipenkov, I.L.; /UC, Berkeley; Koch, H.; Schroeder, T.; /Ruhr U., Bochum /British Columbia U. /Brunel U. /Novosibirsk, IYF /UC, Irvine /UC, Riverside /UC, Santa Barbara /UC, Santa Cruz /Caltech /Cincinnati U. /Colorado U. /Colorado State U. /Dortmund U. /Dresden, Tech. U. /Ecole Polytechnique /Edinburgh U. /INFN, Ferrara /Ferrara U. /INFN, Ferrara /INFN, Ferrara /Ferrara U. /INFN, Ferrara /Frascati /INFN, Genoa /Genoa U. /INFN, Genoa /INFN, Genoa /Genoa U. /INFN, Genoa /INFN, Genoa /Genoa U. /Indian Inst. Tech., Guwahati /Harvard U. /Harvey Mudd Coll. /Heidelberg U. /Humboldt U., Berlin /Imperial Coll., London /Iowa State U. /Iowa State U. /Johns Hopkins U. /Orsay, LAL /LLNL, Livermore /Liverpool U. /Queen Mary, U. of London /Royal Holloway, U. of London /Louisville U. /Mainz U., Inst. Kernphys. /Manchester U. /Maryland U. /Massachusetts U., Amherst /MIT /McGill U. /INFN, Milan /Milan U. /INFN, Milan /INFN, Milan /Milan U. /Mississippi U. /Montreal U. /INFN, Naples /Naples U. /NIKHEF, Amsterdam /NIKHEF, Amsterdam /Notre Dame U. /Ohio State U. /Oregon U. /INFN, Padua /Padua U. /INFN, Padua /INFN, Padua /Padua U. /Paris U., VI-VII /INFN, Perugia /Perugia U. /INFN, Pisa /Pisa U. /INFN, Pisa /Pisa, Scuola Normale Superiore /INFN, Pisa /Pisa U. /INFN, Pisa /Princeton U. /INFN, Rome /INFN, Rome /Rome U. /INFN, Rome /INFN, Rome /Rome U. /INFN, Rome /INFN, Rome /Rome U. /INFN, Rome /INFN, Rome /Rome U. /Rostock U. /Rutherford /DAPNIA, Saclay /SLAC /South Carolina U. /Southern Methodist U. /Stanford U., Phys. Dept. /SUNY, Albany /Tel Aviv U. /Tennessee U. /Texas Nuclear Corp., Austin /Texas U., Dallas /INFN, Turin /Turin U. /INFN, Trieste /Trieste U. /Valencia U. /Victoria U. /Warwick U. /Wisconsin U., Madison

    2011-07-06

    We perform a Dalitz plot analysis of about 100,000 D{sub s}{sup +} decays to K{sup +}K{sup -}{pi}{sup +} and measure the complex amplitudes of the intermediate resonances which contribute to this decay mode. We also measure the relative branching fractions of D{sub s}{sup +} {yields} K{sup +}K{sup +}{pi}{sup -} and D{sub s}{sup +} {yields} K{sup +}K{sup +}K{sup -}. For this analysis we use a 384 fb{sup -1} data sample, recorded by the BABAR detector at the PEP-II asymmetric-energy e{sup +}e{sup -} collider running at center-of-mass energies near 10.58 GeV.

  10. Graph factors modulo k

    DEFF Research Database (Denmark)

    Thomassen, Carsten

    2014-01-01

    We prove a general result on graph factors modulo k . A special case says that, for each natural number k , every (12k−7)-edge-connected graph with an even number of vertices contains a spanning subgraph in which each vertex has degree congruent to k modulo 2k.......We prove a general result on graph factors modulo k . A special case says that, for each natural number k , every (12k−7)-edge-connected graph with an even number of vertices contains a spanning subgraph in which each vertex has degree congruent to k modulo 2k....

  11. High temperature autoclave vacuum seals

    Science.gov (United States)

    Hoffman, J. R.; Simpson, W. G.; Walker, H. M.

    1971-01-01

    Aluminum sheet forms effective sealing film at temperatures up to 728 K. Soft aluminum wire rings provide positive seal between foil and platen. For applications at temperatures above aluminum's service temperature, stainless steel is used as film material and copper wire as sealant.

  12. High Temperature Superconductor Machine Prototype

    DEFF Research Database (Denmark)

    Mijatovic, Nenad; Jensen, Bogi Bech; Træholt, Chresten

    2011-01-01

    A versatile testing platform for a High Temperature Superconductor (HTS) machine has been constructed. The stationary HTS field winding can carry up to 10 coils and it is operated at a temperature of 77K. The rotating armature is at room temperature. Test results and performance for the HTS field...

  13. Thermal annealing of high dose radiation induced damage at room temperature in alkaline. Stored energy, thermoluminescence and coloration; Aniquilacion termica de dano inducido por irradiacion a altas dosis en haluros alcalinos a 300 k. energia almacenda. Termoluminiscencia y coloracion

    Energy Technology Data Exchange (ETDEWEB)

    Delgado, L.

    1980-07-01

    The possible relation between stored energy, thermoluminescence and colour centre annealing in gamma and electron irradiated alkali halides is studied. Thermoluminescence occurs at temperature higher than the temperature at which the main stored energy peak appears. No stored energy release is detected in additively coloured KC1 samples. Plastic deformation and doping with Ca and Sr induce a stored energy spectrum different from the spectrum observed in pure and as cleaved samples, but the amount of stored energy does not change for a given irradiation dose.Capacity of alkali halides to store energy by irradiation increases as the cation size decreases. (Author) 51 refs.

  14. K-He3 and K+K- interactions in the pd→ He3 K+K- reaction

    Science.gov (United States)

    Grishina, V. Yu.; Büscher, M.; Kondratyuk, L. A.

    2007-01-01

    We investigate the K- He3 and K+K- interactions in the reaction pd→ He3 K+K- near threshold and compare our model calculations with data from the MOMO experiment at COSY-Jülich. A large attractive effective K-p amplitude would give a significant K- He3 final-state interaction effect, which is not supported by the experimental data. We also estimate upper limits for the a0(980) and f0(980) contributions to the produced K+K- pairs.

  15. Measurement of Thermal Conductivity of Porcine Liver in the Temperature Range of Cryotherapy and Hyperthermia (250~315k) by A Thermal Sensor Made of A Micron-Scale Enameled Copper Wire.

    Science.gov (United States)

    Jiang, Z D; Zhao, G; Lu, G R

      BACKGROUND: Cryotherapy and hyperthermia are effective treatments for several diseases, especially for liver cancers. Thermal conductivity is a significant thermal property for the prediction and guidance of surgical procedure. However, the thermal conductivities of organs and tissues, especially over the temperature range of both cryotherapy and hyperthermia are scarce. To provide comprehensive thermal conductivity of liver for both cryotherapy and hyperthermia. A hot probe made of stain steel needle and micron-sized copper wire is used for measurement. To verify data processing, both the least square method and the Monte Carlo inversion method are used to determine the hot probe constants, respectively, with reference materials of water and 29.9 % Ca2Cl aqueous solution. Then the thermal conductivities of Hanks solution and pork liver bathed in Hanks solution are measured. The effective length for two methods is nearly the same, but the heat capacity of probe calibrated by the Monte Carlo inversion is temperature dependent. Fairly comprehensive thermal conductivity of porcine liver measured with these two methods in the target temperature range is verified to be similar. We provide an integrated thermal conductivity of liver for cryotherapy and hyperthermia in two methods, and make more accurate predictions possible for surgery. The least square method and the Monte Carlo inversion method have their advantages and disadvantages. The least square method is available for measurement of liquids that not prone to convection or solids in a wide temperature range, while the Monte Carlo inversion method is available for accurate and rapid measurement.

  16. Temperature effects on the pickup process of water group and hydrogen ions - Extensions of 'A theory for low-frequency waves observed at Comet Giacobini-Zinner' by M. L. Goldstein and H. K. Wong

    Science.gov (United States)

    Brinca, Armando L.; Tsurutani, Bruce T.

    1988-01-01

    Cometary heavy ions can resonantly excite hydromagnetic wave activity with spacecraft frequency spectra strongly deviating from the ion cyclotron frequency. The influence of the newborn particle temperature on this effect is assessed, its relevance to the interpretation of the observations is discussed, and an alternative, more efficient mechanism to generate spacecraft frequencies of the order of the proton cyclotron frequency is suggested.

  17. A K Razdan

    Indian Academy of Sciences (India)

    Home; Journals; Pramana – Journal of Physics. A K Razdan. Articles written in Pramana – Journal of Physics. Volume 82 Issue 2 February 2014 pp 385-389 Contributed Papers. Infrared differential absorption lidar for stand-off detection of chemical agents · A K Razdan S Veerabuthiran M K Jindal R K Sharma · More Details ...

  18. P K Kabir

    Indian Academy of Sciences (India)

    M V N Murthy Urjit A yajnik K R S Balaji G Bhattacharyya Amol Dighe Shashikant Dugad N D Hari Dass P K Kabir Kamales Kar D Indumathi John G Learned Debasish Majumdar N K Mondal M V N Murthy S N Nayak Sandip Pakvasa Amitava Raychaudhuri R S Raghavan G Rajasekaran R Ramachandran Alak K Ray Asim ...

  19. P K Das

    Indian Academy of Sciences (India)

    P K Das. Articles written in Pramana – Journal of Physics. Volume 63 Issue 6 December 2004 pp 1359-1365. Working group report: Low energy and flavour physics · Amol Dighe Anirban Kundu K Agashe B Anantanarayan A Chandra A Datta P K Das S P Das A Dighe R Forty D K Ghosh Y -Y Keum A Kundu N Mahajan S ...

  20. Facts about Vitamin K

    Science.gov (United States)

    Facts about Vitamin K 1 R. Elaine Turner and Wendy J. Dahl 2 FCS8666 Figure 1. Vitamin K is mostly found in vegetables, especially green ... ColognePhotos/iStock/Thinkstock, © ColognePhotos Why do we need vitamin K? Vitamin K is one of the fat- ...

  1. C M K Nair

    Indian Academy of Sciences (India)

    Home; Journals; Bulletin of Materials Science. C M K Nair. Articles written in Bulletin of Materials Science. Volume 24 Issue 2 April 2001 pp 249-252 Crystal Growth. Thermal behaviour of strontium tartrate single crystals grown in gel · M H Rahimkutty K Rajendra Babu K Sreedharan Pillai M R Sudarsana Kumar C M K Nair.

  2. Temperature profiles from MBT casts from the CUMULUS from Ocean Weather Station A (OWS-A), J (OWS-J), K (OWS-K), and M (OWS-M) in the North Atlantic Ocean from 20 August 1971 to 11 December 1972 (NODC Accession 7300137)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Bathythermograph data were collected from the CUMULUS within a 1-mile radius of Ocean Weather Station A (6200N 03300W), J (5230N 02000W), K (4500N 01600W), M (6600N...

  3. Temperature profiles from MBT casts from the CUMULUS from Ocean Weather Station A (OWS-A), J (OWS-J), K (OWS-K), and M (OWS-M) in the North Atlantic Ocean from 10 January 1973 to 30 December 1973 (NODC Accession 7400186)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Bathythermograph data were collected from the CUMULUS within a 1-mile radius of Ocean Weather Station A (6200N 03300W), J (5230N 02000W), K (4500N 01600W), M (6600N...

  4. K$_{-}$ and K$_{-}$ polarizability from kaonic atoms

    CERN Document Server

    Backenstoss, Gerhard; Bergström, I; Bunaciu, T; Egger, J; Hagelberg, R; Hultberg, S; Koch, H; Lynen, Y; Ritter, H G; Schwitter, A; Tauscher, L

    1973-01-01

    The K/sup -/ mass was determined from kaonic atomic X-rays from Au and Ba to be 493.691+or-0.040 MeV. An upper limit for the polarizability of the K/sup -/ was found to be 0.020 fm/sup 3/ at 90% confidence. (18 refs).

  5. Some Topological Properties of the Derivation Algebra D(K/k) for a Field Extension K/k

    OpenAIRE

    KIKUCHI, Teppei

    1982-01-01

    Let K be a field extension of a field k, and D(K/k) be its derivation algebra. In the previous paper [1], we gave some topological considerations on D(K/k). And we showed, for example, that D(K/k) is dense in Homk(K,K) with respect to the finite topology if and only if the center Z(D)(K/k)) of D(K/k) coincides with k. On the other hand, we know already that D(K/k)=D(K/ks) and Z(D(K/ks))⊃ks (where ks denotes the separable algebraic closure of k in K) and that if [K:k] is finite then D(K/k) is ...

  6. Temperature Dependences of the Quantum-Mechanical and Semi-Classical Spectral-Line Widths and the Separation 0 of the Impact and Non-Impact Regions for an Ar-Perturbed/K-Radiator System

    Directory of Open Access Journals (Sweden)

    W. C. Kreye

    2010-01-01

    Full Text Available Quantum-mechanical and semi-classical spectral-line shapes are computed at =400, 800, and 1000 K for the line core of the 5802 Å line of the Ar-Perturbed/K-Radiator system. HWHMs ('s are measured from computed full spectral-line shapes. The final-state pseudopotential is for the 721/2 state, and the initial-state potential is for the 423/2,3/2 state. Three high-pressure (P log(—versus—log( curves, corresponding to the non-impact region, intersect a similar set of low-P, impact-region curves at intersections, 0's. Similarly, for two sets of log(—versus—log( curves, which yield intersections, 0's, where is the perturber density. These 0's and 0's separate the two regions and represent the upper limits of the impact regions. A specific validity condition for the impact region is given by the equation ≤0. From an earlier spectroscopic, Fabry-Perot paper, expt=0.021 cm−1 at =400 K and =10 torr. Two theoretical values, theor=0.025 and 0.062 cm−1 corresponding to two different pseudo-potentials, are reported. Two -dependent figures are given, in which the first shows an increase in the impact region with , based on as the basic parameter, and the second which shows a decrease in the impact region with , based on as the basic parameter.

  7. Temperature-dependence of the ultrafast intermolecular dynamics of Amides: Formamide, N-methylformamide, N,N-dimethylformamide, N- methylacetamide, and N-methylpropionamide from 290-370 K

    Energy Technology Data Exchange (ETDEWEB)

    Castner, E.W.

    1996-06-01

    Femtosecond optical-heterodyne detected, Raman-induced Car effect spectroscopy was used to characterize the full spectrum of the intermolecular vibrational and diffusive dynamics for these five amides, which are among the most interesting organic solvents. 50-fs, transform-limited pulses were used to excite all the intermolecular motions in the 0 to 400 cm{sup -1} range. Clear differences were found in the response vs temperature. 2 figs.

  8. Comments on "Synthesis aspects, structural, spectroscopic, antimicrobial and room temperature ferromagnetism of zinc iodide complex with Schiff based ligand" by K. Shakila and S. Kalainathan, Spectrochim. Acta 135 A (2015) 1059-1065.

    Science.gov (United States)

    Srinivasan, Bikshandarkoil R; Nadkarni, V S

    2016-06-15

    Shakila and Kalainathan report on the synthetic and structural aspects of a zinc iodide complex with Schiff based ligand, which exhibits room temperature ferromagnetism. In this comment, many points of criticism, concerning the characterization of this so called zinc iodide complex of Schiff based ligand are highlighted to prove that the title paper is completely erroneous. Copyright © 2016 Elsevier B.V. All rights reserved.

  9. Overview of Air Liquide refrigeration systems between 1.8 K and 200 K

    Science.gov (United States)

    Gondrand, C.; Durand, F.; Delcayre, F.; Crispel, S.; Baguer, G. M. Gistau

    2014-01-01

    Cryogenic refrigeration systems are necessary for numerous applications. Gas purification and distillation require temperatures between 15 K and 200 K depending on the application, space simulation chambers down to 15 K, superconductivity between 1.8 K and up to 75 K (magnets, cavities or HTS devices like cables, FCL, SMES, etc), Cold Neutron Sources between 15 and 20 K, etc. Air Liquide Advanced Technologies is designing and manufacturing refrigerators since 60 years to satisfy those needs. The step by step developments achieved have led to machines with higher efficiency and reliability. In 1965, reciprocating compressors and Joule Thomson expansion valves were used. In 1969, centripetal expanders began to be used. In 1980, oil lubricated screw compressors took the place of reciprocating compressors and a standard range of Claude cycle refrigerators was developed: the HELIAL series. 1980 was also the time for cryogenic centrifugal compressor development. In 2011, driven by the need for lower operational cost (high efficiency and low maintenance), cycle oil free centrifugal compressors on magnetic bearings were introduced instead of screw compressors. The power extracted by centripetal expanders was recovered. Based on this technology, a range of Turbo-Brayton refrigerators has been designed for temperatures between 40 K and 150 K. On-going development will enable widening the range of Turbo-Brayton refrigerators to cryogenic temperatures down to 15 K.. Cryogenic centrifugal circulators have been developed in order to answer to an increasing demand of 4 K refrigerators able to distribute cold power.

  10. Cryogenic Capacitors for Low-Temperature Power Systems Project

    Data.gov (United States)

    National Aeronautics and Space Administration — TRS Technologies proposes to develop low-temperature multilayer ceramic capacitors (MLCCs) capable of operating at cyrogenic temperatures (<77K). These capacitors...

  11. Observation of B+ --> K0bar K+ and B0 --> K0 K0bar

    CERN Document Server

    Aubert, B; Boutigny, D; Couderc, F; Karyotakis, Yu; Lees, J P; Poireau, V; Tisserand, V; Zghiche, A; Graugès-Pous, E; Palano, A; Chen, J C; Qi, N D; Rong, G; Wang, P; Zhu, Y S; Eigen, G; Ofte, I; Stugu, B; Abrams, G S; Battaglia, M; Brown, D N; Button-Shafer, J; Cahn, R N; Charles, E; Gill, M S; Groysman, Y; Jacobsen, R G; Kadyk, J A; Kerth, L T; Kolomensky, Yu G; Kukartsev, G; Lynch, G; Mir, L M; Orimoto, T J; Pripstein, M; Roe, N A; Ronan, M T; Wenzel, W A; Del, P; Amo Sanchez; Barrett, M; Ford, K E; Harrison, T J; Hart, A J; Hawkes, C M; Watson, A T; Held, T; Koch, H; Lewandowski, B; Pelizaeus, M; Peters, K; Schröder, T; Steinke, M; Boyd, J T; Burke, J P; Cottingham, W N; Walker, D; Asgeirsson, D J; Çuhadar-Dönszelmann, T; Fulsom, B G; Hearty, C; Knecht, N S; Mattison, T S; McKenna, J A; Khan, A; Kyberd, P; Saleem, M; Sherwood, D J; Teodorescu, L; Blinov, V E; Bukin, A D; Druzhinin, V P; Golubev, V B; Onuchin, A P; Serednyakov, S I; Skovpen, Yu I; Solodov, E P; Todyshev, K Yu; Bondioli, M; Bruinsma, M; Chao, M; Curry, S; Eschrich, I; Kirkby, D; Lankford, A J; Lund, P; Mandelkern, M A; Mommsen, R K; Röthel, W; Stoker, D P; Abachi, S; Buchanan, C; Foulkes, S D; Gary, J W; Long, O; Shen, B C; Wang, K; Zhang, L; Hadavand, H K; Hill, E J; Paar, H P; Rahatlou, S; Sharma, V; Berryhill, J W; Campagnari, C; Cunha, A; Dahmes, B; Hong, T M; Kovalskyi, D; Richman, J D; Beck, T W; Eisner, A M; Flacco, C J; Heusch, C A; Kroseberg, J; Lockman, W S; Nesom, G; Schalk, T; Schumm, B A; Seiden, A; Spradlin, P; Williams, D C; Wilson, M G; Albert, J; Chen, E; Dvoretskii, A; Fang, F; Hitlin, D G; Narsky, I; Piatenko, T; Porter, F C; Ryd, A; Mancinelli, G; Meadows, B T; Mishra, K; Sokoloff, M D; Blanc, F; Bloom, P C; Chen, S; Ford, W T; Hirschauer, J F; Kreisel, A; Nagel, M; Nauenberg, U; Olivas, A; Ruddick, W O; Smith, J G; Ulmer, K A; Wagner, S R; Zhang, J; Chen, A; Eckhart, E A; Soffer, A; Toki, W H; Wilson, R J; Winklmeier, F; Zeng, Q; Altenburg, D D; Feltresi, E; Hauke, A; Jasper, H; Merkel, J; Petzold, A; Spaan, B; Brandt, T; Klose, V; Lacker, H M; Mader, W F; Nogowski, R; Schubert, J; Schubert, K R; Schwierz, R; Sundermann, J E; Volk, A; Bernard, D; Bonneaud, G R; Latour, E; Thiebaux, C; Verderi, M; Clark, P J; Gradl, W; Muheim, F; Playfer, S; Robertson, A I; Xie, Y; Andreotti, M; Bettoni, D; Bozzi, C; Calabrese, R; Cibinetto, G; Luppi, E; Negrini, M; Petrella, A; Piemontese, L; Prencipe, E; Anulli, F; Baldini-Ferroli, R; Calcaterra, A; De Sangro, R; Finocchiaro, G; Pacetti, S; Patteri, P; Peruzzi, I M; Piccolo, M; Rama, M; Zallo, A; Buzzo, A; Contri, R; Lo, M; Lo Vetere, M; Macri, M M; Monge, M R; Passaggio, S; Patrignani, C; Robutti, E; Santroni, A; Tosi, S; Brandenburg, G; Chaisanguanthum, K S; Morii, M; Wu, J; Dubitzky, R S; Marks, J; Schenk, S; Uwer, U; Bard, D J; Bhimji, W; Bowerman, D A; Dauncey, P D; Egede, U; Flack, R L; Nash, J A; Nikolich, M B; Panduro-Vazquez, W; Behera, P K; Chai, X; Charles, M J; Mallik, U; Meyer, N T; Ziegler, V; Cochran, J; Crawley, H B; Dong, L; Eyges, V; Meyer, W T; Prell, S; Rosenberg, E I; Rubin, A E; Gritsan, A V; Denig, A G; Fritsch, M; Schott, G; Arnaud, N; Davier, M; Grosdidier, G; Höcker, A; Le Diberder, F R; Lepeltier, V; Lutz, A M; Oyanguren, A; Pruvot, S; Rodier, S; Roudeau, P; Schune, M H; Stocchi, A; Wang, W F; Wormser, G; Cheng, C H; Lange, D J; Wright, D M; Chavez, C A; Forster, I J; Fry, J R; Gabathuler, E; Gamet, R; George, K A; Hutchcroft, D E; Payne, D J; Schofield, K C; Touramanis, C; Bevan, A J; Di Lodovico, F; Menges, W; Sacco, R; Cowan, G; Flächer, H U; Hopkins, D A; Jackson, P S; McMahon, T R; Ricciardi, S; Salvatore, F; Wren, A C; Davis, C L; Allison, J; Barlow, N R; Barlow, R J; Chia, Y M; Edgar, C L; Lafferty, G D; Naisbit, M T; Williams, J C; Yi, J I; Chen, C; Hulsbergen, W D; Jawahery, A; Lae, C K; Roberts, D A; Simi, G; Blaylock, G; Dallapiccola, C; Hertzbach, S S; Li, X; Moore, T B; Saremi, S; Stängle, H; Cowan, R; Sciolla, G; Sekula, S J; Spitznagel, M; Taylor, F; Yamamoto, R K; Kim, H; Mclachlin, S E; Patel, P M; Robertson, S H; Lazzaro, A; Lombardo, V; Palombo, F; Bauer, J M; Cremaldi, L; Eschenburg, V; Godang, R; Kroeger, R; Sanders, D A; Summers, D J; Zhao, H W; Brunet, S; Côté, D; Simard, M; Taras, P; Viaud, F B; Nicholson, H; Cavallo, N; De Nardo, Gallieno; Fabozzi, F; Gatto, C; Lista, L; Monorchio, D; Paolucci, P; Piccolo, D; Sciacca, C; Baak, M A; Raven, G; Snoek, H L; Jessop, C P; LoSecco, J M; Allmendinger, T; Benelli, G; Corwin, L A; Gan, K K; Honscheid, K; Hufnagel, D; Jackson, P D; Kagan, H; Kass, R; Rahimi, A M; Regensburger, J J; Ter-Antonian, R; Wong, Q K; Blount, N L; Brau, J E; Frey, R; Igonkina, O; Kolb, J A; Lu, M; Rahmat, R; Sinev, N B; Strom, D; Strube, J; Torrence, E; Gaz, A; Margoni, M; Morandin, M; Pompili, A; Posocco, M; Rotondo, M; Simonetto, F; Stroili, R; Voci, C; Benayoun, M; Briand, H; Chauveau, J; David, P; Del, L; Buono; La Vaissière, C de; Hamon, O; Hartfiel, B L; Leruste, P; Malcles, J; Ocariz, J; Roos, L; Therin, G; Gladney, L; Biasini, M; Covarelli, R; Angelini, C; Batignani, G; Bettarini, S; Bucci, F; Calderini, G; Carpinelli, M; Cenci, R; Forti, F; Giorgi, M A; Lusiani, A; Marchiori, G; Mazur, M A; Morganti, M; Neri, N; Paoloni, E; Rizzo, G; Walsh, J J; Haire, M; Judd, D; Wagoner, D E; Biesiada, J; Danielson, N; Elmer, P; Lau, Y P; Lü, C; Olsen, J; Smith, A J S; Telnov, A V; Bellini, F; Cavoto, G; D'Orazio, A; Del Re, D; Di Marco, E; Faccini, R; Ferrarotto, F; Ferroni, F; Gaspero, M; Li Gioi, L; Mazzoni, M A; Morganti, S; Piredda, G; Polci, F; Safai-Tehrani, F; Voena, C; Ebert, M; Schröder, H; Waldi, R; Adye, T; De Groot, N; Franek, B; Olaiya, E O; Wilson, F F; Aleksan, R; Emery, S; Gaidot, A; Ganzhur, S F; Hamel de Monchenault, G; Kozanecki, Witold; Legendre, M; Vasseur, G; Yéche, C; Zito, M; Chen, X R; Liu, H; Park, W; Purohit, M V; Wilson, J R; Allen, M T; Aston, D; Bartoldus, R; Bechtle, P; Berger, N; Claus, R; Coleman, J P; Convery, M R; Cristinziani, M; Dingfelder, J C; Dorfan, J; Dubois-Felsmann, G P; Dujmic, D; Dunwoodie, W M; Field, R C; Glanzman, T; Gowdy, S J; Graham, M T; Grenier, P; Halyo, V; Hast, C; Hrynóva, T; Innes, W R; Kelsey, M H; Kim, P; Leith, D W G S; Li, S; Luitz, S; Lüth, V; Lynch, H L; MacFarlane, D B; Marsiske, H; Messner, R; Müller, D R; O'Grady, C P; Ozcan, V E; Perazzo, A; Perl, M; Pulliam, T; Ratcliff, B N; Roodman, A; Salnikov, A A; Schindler, R H; Schwiening, J; Snyder, A; Stelzer, J; Su, D; Sullivan, M K; Suzuki, K; Swain, S K; Thompson, J M; Vavra, J; Van Bakel, N; Weaver, M; Weinstein, A J R; Wisniewski, W J; Wittgen, M; Wright, D H; Yarritu, A K; Yi, K; Young, C C; Burchat, P R; Edwards, A J; Majewski, S A; Petersen, B A; Roat, C; Wilden, L; Ahmed, S; Alam, M S; Bula, R; Ernst, J A; Jain, V; Pan, B; Saeed, M A; Wappler, F R; Zain, S B; Bugg, W; Krishnamurthy, M; Spanier, S M; Eckmann, R; Ritchie, J L; Satpathy, A; Schilling, C J; Schwitters, R F; Izen, J M; Lou, X C; Ye, S; Bianchi, F; Gallo, F; Gamba, D; Bomben, M; Bosisio, L; Cartaro, C; Cossutti, F; Della Ricca, G; Dittongo, S; Lanceri, L; Vitale, L; Azzolini, V; Lopez-March, N; Martínez-Vidal, F; Banerjee, Sw; Bhuyan, B; Brown, C M; Fortin, D; Hamano, K; Kowalewski, R V; Nugent, I M; Roney, J M; Sobie, R J; Back, J J; Harrison, P F; Latham, T E; Mohanty, G B; Pappagallo, M; Band, H R; Chen, X; Cheng, B; Dasu, S; Datta, M; Flood, K T; Hollar, J J; Kutter, P E; Mellado, B; Mihályi, A; Pan, Y; Pierini, M; Prepost, R; Wu, S L; Yu, Z; Neal, H

    2006-01-01

    We report observations of the b --> d penguin-dominated decays B+ --> K0bar K+ and B0 --> K0 K0bar in approximately 350 million Upsilon(4S) --> BBbar decays collected with the BaBar detector. We measure the branching fractions B(B+ --> K0bar K+) = (1.61 +/- 0.44 +/- 0.09) * 10^-6 and B(B0 --> K0 K0bar) = (1.08 +/- 0.28 +/- 0.11) * 10^-6, and the CP-violating charge asymmetry A_{CP}(K0bar K+) = 0.10 +/- 0.26 +/- 0.03. Using a vertexing technique previously employed in several analyses of all-neutral final states containing kaons, we report the first measurement of time-dependent CP-violating asymmetries in B0 --> K0 K0bar, obtaining S = -1.28 +0.80/-0.73 +0.11/-0.16 and C = -0.40 +/- 0.41 +/- 0.06. We also report improved measurements of the branching fraction B(B0 --> K0 pi+) = (23.9 +/- 1.1 +/- 1.0) * 10^-6 and CP-violating charge asymmetry A_{CP}(K0 pi+) = -0.029 +/- 0.039 +/- 0.010.

  12. Fiber Sagnac interferometer temperature sensor

    Energy Technology Data Exchange (ETDEWEB)

    Starodumov, A.N.; Zenteno, L.A.; Monzon, D.; De La Rosa, E. [Centro de Investigaciones en Optica, 37150 Leon, Gto (Mexico)

    1997-01-01

    A modified Sagnac interferometer-based fiber temperature sensor is proposed. Polarization independent operation and high temperature sensitivity of this class of sensors make them cost effective instruments for temperature measurements. A comparison of the proposed sensor with Bragg grating and long-period grating fiber sensors is derived. A temperature-induced spectral displacement of 0.99 nm/K is demonstrated for an internal stress birefringent fiber-based Sagnac interferometer. {copyright} {ital 1997 American Institute of Physics.}

  13. Insight into the local magnetic environments and deuteron mobility in jarosite (AFe3(SO4)2(OD)6, A = K, Na, D3O) and hydronium alunite ((D3O)Al3(SO4)2(OD,OD2)6), from variable temperature 2H MAS NMR spectroscopy

    DEFF Research Database (Denmark)

    Nielsen, Ulla Gro; Heinmaa, Ivo; Samoson, Ago

    2011-01-01

    to the different temperature dependence of their isotropic shifts. An activation energy of 6.3(4) kJ/mol is determined for the D3O+ motion in the isostructural compound D3OAl3(SO4)2(OD)6. Our NMR results support theories that ascribes the spin glass behavior of (H3O)Fe3(SO4)2(OD)6 is to disorder of the D3O+ ion...... and/or a less distorted Fe coordination environment. No sign of proton transfer reactions from the D3O+ ion to the framework is observed....

  14. BILATERAL KEY COMPARISON SIM.T-K6.1 ON HUMIDITY STANDARDS IN THE DEW/FROST-POINT TEMPERATURE RANGE FROM −25 °C TO +20 °C

    Science.gov (United States)

    Meyer, C.W.; Hill, K.D.

    2015-01-01

    A Regional Metrology Organization (RMO) Key Comparison of dew/frost point temperatures was carried out by the National Institute of Standards and Technology (NIST, USA) and the National Research Council (NRC, Canada) between December 2014 and April, 2015. The results of this comparison are reported here, along with descriptions of the humidity laboratory standards for NIST and NRC and the uncertainty budget for these standards. This report also describes the protocol for the comparison and presents the data acquired. The results are analyzed, determining degree of equivalence between the dew/frost-point standards of NIST and NRC. PMID:26663952

  15. BILATERAL KEY COMPARISON SIM.T-K6.1 ON HUMIDITY STANDARDS IN THE DEW/FROST-POINT TEMPERATURE RANGE FROM -25 °C TO +20 °C.

    Science.gov (United States)

    Meyer, C W; Hill, K D

    A Regional Metrology Organization (RMO) Key Comparison of dew/frost point temperatures was carried out by the National Institute of Standards and Technology (NIST, USA) and the National Research Council (NRC, Canada) between December 2014 and April, 2015. The results of this comparison are reported here, along with descriptions of the humidity laboratory standards for NIST and NRC and the uncertainty budget for these standards. This report also describes the protocol for the comparison and presents the data acquired. The results are analyzed, determining degree of equivalence between the dew/frost-point standards of NIST and NRC.

  16. TEMPERATURE INDEPENDENT PHOTOLUMINESCENCE ...

    Indian Academy of Sciences (India)

    8

    [1] C.A.K. Gouvˆea, F. Wypych, S.G. Moraes, N. Dur´an, P. Peralta-Zamora, Semiconductor- assisted photocatalytic degradation of reactive dyes in aqueous solution, Chemosphere. 427(2000) 40. [2] D.C Look, Equation of state for the study of temperature dependence of volume thermal expansion of nanomaterials, Mater.

  17. Vitamin K and cancer.

    Science.gov (United States)

    Dahlberg, Sofia; Ede, Jacob; Schött, Ulf

    2017-12-01

    Subclinical vitamin K deficits refer to carboxylation defects of different types of vitamin K-dependent hepatic and extrahepatic so-called Gla proteins without prolongation of the prothrombin time. This condition has been reported in different clinical situations due to insufficient supply or malabsorption of vitamin K as well as drug interactions. This review discusses the effects of different vitamin K subspecies on tumour growth and the possible anti-tumour effects of increased vitamin K intake. Blocking carboxylation of vitamin K-dependent proteins with warfarin anticoagulation - what are the risks/benefits for carcinogenesis? Previous studies on both heparin and low molecular weight heparin blocking of the vitamin K-dependent factors X and II have shown tumour suppressive effects. Vitamin K has anti-inflammatory effects that could also impact carcinogenesis, but little data exists on this subject.

  18. Experimental study of psi' decays to K+K- pi^0 and K+K- eta

    CERN Document Server

    Ablikim, M; Ambrose, D J; An, F F; An, Q; An, Z H; Bai, J Z; Ban, Y; Becker, J; Berger, N; Bertani, M; Bian, J M; Boger, E; Bondarenko, O; Boyko, I; Briere, R A; Bytev, V; Cai, X; Cakir, O; Calcaterra, A; Cao, G F; Cetin, S A; Chang, J F; Chelkov, G; Chen, G; Chen, H S; Chen, J C; Chen, M L; Chen, S J; Chen, Y; Chen, Y B; Cheng, H P; Chu, Y P; Cronin-Hennessy, D; Dai, H L; Dai, J P; Dedovich, D; Deng, Z Y; Denig, A; Denysenko, I; Destefanis, M; Ding, W M; Ding, Y; Dong, L Y; Dong, M Y; Du, S X; Fang, J; Fang, S S; Fava, L; Feldbauer, F; Feng, C Q; Ferroli, R B; Fu, C D; Fu, J L; Gao, Y; Geng, C; Goetzen, K; Gong, W X; Gradl, W; Greco, M; Gu, M H; Gu, Y T; Guan, Y H; Guo, A Q; Guo, L B; Guo, Y P; Han, Y L; Hao, X Q; Harris, F A; He, K L; He, M; He, Z Y; Held, T; Heng, Y K; Hou, Z L; Hu, H M; Hu, J F; Hu, T; Huang, B; Huang, G M; Huang, J S; Huang, X T; Huang, Y P; Hussain, T; Ji, C S; Ji, Q; Ji, X B; Ji, X L; Jia, L K; Jiang, L L; Jiang, X S; Jiao, J B; Jiao, Z; Jin, D P; Jin, S; Jing, F F; Kalantar-Nayestanaki, N; Kavatsyuk, M; Kuehn, W; Lai, W; Lange, J S; Li, C H; Li, Cheng; Li, Cui; Li, D M; Li, F; Li, G; Li, H B; Li, J C; Li, K; Li, Lei; Li, N B; Li, Q J; Li, S L; Li, W D; Li, W G; Li, X L; Li, X N; Li, X Q; Li, X R; Li, Z B; Liang, H; Liang, Y F; Liang, Y T; Liao, G R; Liao, X T; Liu, B J; Liu, C L; Liu, C X; Liu, C Y; Liu, F H; Liu, Fang; Liu, Feng; Liu, H; Liu, H B; Liu, H H; Liu, H M; Liu, H W; Liu, J P; Liu, K Y; Liu, Kai; Liu, Kun; Liu, P L; Liu, S B; Liu, X; Liu, X H; Liu, Y; Liu, Y B; Liu, Z A; Liu, Zhiqiang; Liu, Zhiqing; Loehner, H; Lu, G R; Lu, H J; Lu, J G; Lu, Q W; Lu, X R; Lu, Y P; Luo, C L; Luo, M X; Luo, T; Luo, X L; Lv, M; Ma, C L; Ma, F C; Ma, H L; Ma, Q M; Ma, S; Ma, T; Ma, X Y; Ma, Y; Maas, F E; Maggiora, M; Malik, Q A; Mao, H; Mao, Y J; Mao, Z P; Messchendorp, J G; Min, J; Min, T J; Mitchell, R E; Mo, X H; Morales, C Morales; Motzko, C; Muchnoi, N Yu; Muramatsu, H; Nefedov, Y; Nicholson, C; Nikolaev, I B; Ning, Z; Olsen, S L; Ouyang, Q; Pacetti, S; Park, J W; Pelizaeus, M; Peng, H P; Peters, K; Ping, J L; Ping, R G; Poling, R; Prencipe, E; Qi, M; Qian, S; Qiao, C F; Qin, X S; Qin, Y; Qin, Z H; Qiu, J F; Rashid, K H; Rong, G; Ruan, X D; Sarantsev, A; Schaefer, B D; Schulze, J; Shao, M; Shen, C P; Shen, X Y; Sheng, H Y; Shepherd, M R; Song, X Y; Spataro, S; Spruck, B; Sun, D H; Sun, G X; Sun, J F; Sun, S S; Sun, X D; Sun, Y J; Sun, Y Z; Sun, Z J; Sun, Z T; Tang, C J; Tang, X; Tapan, I; Thorndike, E H; Tian, H L; Toth, D; Ullrich, M; Varner, G S; Wang, B; Wang, B Q; Wang, K; Wang, L L; Wang, L S; Wang, M; Wang, P; Wang, P L; Wang, Q; Wang, Q J; Wang, S G; Wang, X L; Wang, Y D; Wang, Y F; Wang, Y Q; Wang, Z; Wang, Z G; Wang, Z Y; Wei, D H; Weidenkaff, P; Wen, Q G; Wen, S P; Werner, M; Wiedner, U; Wu, L H; Wu, N; Wu, S X; Wu, W; Wu, Z; Xia, L G; Xiao, Z J; Xie, Y G; Xiu, Q L; Xu, G F; Xu, G M; Xu, H; Xu, Q J; Xu, X P; Xu, Z R; Xue, F; Xue, Z; Yan, L; Yan, W B; Yan, Y H; Yang, H X; Yang, Y; Yang, Y X; Ye, H; Ye, M; Ye, M H; Yu, B X; Yu, C X; Yu, J S; Yu, S P; Yuan, C Z; Yuan, W L; Yuan, Y; Zafar, A A; Zallo, A; Zeng, Y; Zhang, B X; Zhang, B Y; Zhang, C C; Zhang, D H; Zhang, H H; Zhang, H Y; Zhang, J; Zhang, J Q; Zhang, J W; Zhang, J Y; Zhang, J Z; Zhang, S H; Zhang, T R; Zhang, X J; Zhang, X Y; Zhang, Y; Zhang, Y H; Zhang, Y S; Zhang, Z P; Zhang, Z Y; Zhao, G; Zhao, H S; Zhao, J W; Zhao, K X; Zhao, Lei; Zhao, Ling; Zhao, M G; Zhao, Q; Zhao, S J; Zhao, T C; Zhao, X H; Zhao, Y B; Zhao, Z G; Zhemchugov, A; Zheng, B; Zheng, J P; Zheng, Y H; Zheng, Z P; Zhong, B; Zhong, J; Zhou, L; Zhou, X K; Zhou, X R; Zhu, C; Zhu, K; Zhu, K J; Zhu, S H; Zhu, X L; Zhu, X W; Zhu, Y C; Zhu, Y M; Zhu, Y S; Zhu, Z A; Zhuang, J; Zou, B S; Zou, J H; Zuo, J X

    2012-01-01

    Using $(106\\pm4)\\times 10^6$ $\\psip$ events accumulated with the BESIII detector at the BEPCII $e^+e^-$ collider, we present measurements of the branching fractions for psi' decays to $K^{+}K^{-}\\pi^{0}$ and $K^{+}K^{-}\\eta$. In these final states, the decay $\\psi'\\to K_2^{*}(1430)^+K^-+c.c.$ is observed for the first time, and its branching fraction is measured to be $(7.12\\pm{0.62}{\\rm (stat.)}^{+1.13}_{-0.61}{\\rm (syst.)})\\times 10^{-5}$, which indicates a violation of the helicity selection rule in $\\psip$ decays. The branching fractions of $\\psi'\\to K^*(892)^+K^-+c.c., \\phi\\eta, \\phi\\pi^0$ are also measured. The measurements are used to test the QCD predictions on charmonium decays.

  19. K Veera Brahmam

    Indian Academy of Sciences (India)

    Home; Journals; Bulletin of Materials Science. K Veera Brahmam. Articles written in Bulletin of Materials Science. Volume 28 Issue 5 August 2005 pp 411-414 Single Crystals. Crystal growth and reflectivity studies of Zn1–MnTe crystals · K Veera Brahmam D Raja Reddy B K Reddy · More Details Abstract Fulltext PDF.

  20. Sanjay K Yadav

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Earth System Science. Sanjay K Yadav. Articles written in Journal of Earth System Science. Volume 120 Issue 2 April 2011 pp 205-213. One-dimensional unsteady solute transport along unsteady flow through inhomogeneous medium · Sanjay K Yadav Atul Kumar Dilip K Jaiswal Naveen Kumar.

  1. P K SOOD

    Indian Academy of Sciences (India)

    Home; Journals; Sadhana. P K SOOD. Articles written in Sadhana. Volume 42 Issue 3 March 2017 pp 365-378. Machinability of hypereutectic cast Al–Si alloys processed by SSM processing technique · P K SOOD RAKESH SEHGAL D K DWIVEDI · More Details Abstract Fulltext PDF. Experimental investigation carried out ...

  2. P K Arora

    Indian Academy of Sciences (India)

    Home; Journals; Sadhana. P K Arora. Articles written in Sadhana. Volume 38 Issue 3 June 2013 pp 421-428. Recent development of cellular manufacturing systems · P K Arora A Haleem M K Singh · More Details Abstract Fulltext PDF. Cellular manufacturing system has been proved a vital approach for batch and job shop ...

  3. P K Kalra

    Indian Academy of Sciences (India)

    Home; Journals; Sadhana. P K Kalra. Articles written in Sadhana. Volume 25 Issue 2 April 2000 pp 193-203. Parameter estimation using compensatory neural networks · M Sinha P K Kalra K Kumar · More Details Abstract Fulltext PDF. Proposed here is a new neuron model, a basis for Compensatory Neural Network ...

  4. Binay K Dutta

    Indian Academy of Sciences (India)

    Home; Journals; Bulletin of Materials Science. Binay K Dutta. Articles written in Bulletin of Materials Science. Volume 33 Issue 2 April 2010 pp 185-190 Fly Ash. Effect of curing conditions and ionic additives on properties of fly ash–lime compacts · Saikat Maitra Farooq Ahmad Ananta K Das Santanu Das Binay K Dutta.

  5. A K Verma

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Earth System Science. A K Verma. Articles written in Journal of Earth System Science. Volume 114 Issue 1 February 2005 pp 75-86. A comparative study of ANN and Neuro-fuzzy for the prediction of dynamic constant of rockmass · T N Singh R Kanchan A K Verma K Saigal · More Details Abstract ...

  6. K-K-K-Kuninga kõne / Peter Conradi ; tõlkinud Kadri Karro

    Index Scriptorium Estoniae

    Conradi, Peter

    2011-01-01

    The Sunday Timesi ajakirjanik valgustab filmi "Kuninga kõne" (režissöör Tom Hooper, Inglise-Austraalia-USA, 2010) tagamaid. Film räägib kuningas George VI elust ja tema kõnedefektist, kogelemisest. Kuningat aitas Austraalia päritolu kõneterapeut Lionel Logue. Filmi stsenaariumi kirjutas David Seidler

  7. S K Prashant

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Chemical Sciences. S K Prashant. Articles written in Journal of Chemical Sciences. Volume 121 Issue 5 September 2009 pp 647-654. Poly (vinyl alcohol) hydrogel membrane as electrolyte for direct borohydride fuel cells · N A Choudhury S K Prashant S Pitchumani P Sridhar A K Shukla.

  8. V K Gaur

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Earth System Science. V K Gaur. Articles written in Journal of Earth System Science. Volume 109 Issue 1 March 2000 pp 1-3. Editorial · V K Gaur · More Details Fulltext PDF. Volume 109 Issue 4 December 2000 pp 393-394. Editorial · V K Gaur · More Details Fulltext PDF. Volume 112 Issue 3 ...

  9. On $k$-stellated and $k$-stacked spheres

    OpenAIRE

    Bagchi, Bhaskar; Datta, Basudeb

    2012-01-01

    We introduce the class $\\Sigma_k(d)$ of $k$-stellated (combinatorial) spheres of dimension $d$ ($0 \\leq k \\leq d + 1$) and compare and contrast it with the class ${\\cal S}_k(d)$ ($0 \\leq k \\leq d$) of $k$-stacked homology $d$-spheres. We have $\\Sigma_1(d) = {\\cal S}_1(d)$, and $\\Sigma_k(d) \\subseteq {\\cal S}_k(d)$ for $d \\geq 2k - 1$. However, for each $k \\geq 2$ there are $k$-stacked spheres which are not $k$-stellated. The existence of $k$-stellated spheres which are not $k$-stacked remains...

  10. A grid of synthetic spectra for the determination of effective temperature, gravity and metallicity of F, G, and K stars. I - Description of the method. II - Application to 41 stellar spectra taken in the Basel field of SA 141

    Science.gov (United States)

    Cayrel, R.; Perrin, M.-N.; Barbuy, B.; Buser, R.

    1991-07-01

    The computation of a grid of synthetic spectra in the wavelength region λλ4780-5300 Å is described. With the use of this grid, a method is developed for deriving the stellar parameters temperature, gravity and metallicity from a low-resolution spectrum. The use of the grid is tested for 20 reference stars, in two ways. The stellar parameters for these 20 stars are derived (1) directly from the grid, (2) using the synthetic grid in conjunction with the observed spectrum of another reference star. A best fit is obtained by the second method, i.e., by using the grid in combination with a number of standard stars, in this way establishing corrections to the parameters obtained exclusively from the grid.

  11. BILATERAL KEY COMPARISON SIM.T-K6.5 ON HUMIDITY STANDARDS IN THE DEW/FROST-POINT TEMPERATURE RANGE FROM -30 °C TO +20 °C.

    Science.gov (United States)

    Meyer, C W; Solano, A

    2016-01-01

    A Regional Metrology Organization (RMO) Key Comparison of dew/frost point temperatures over the range -30 °C TO +20 °C was carried out by the National Institute of Standards and Technology (NIST, USA) and the Laboratorio Costarricense de Metrología (LACOMET, Costa Rica), between February 2015 and August 2015. The results of this comparison are reported here, along with descriptions of the humidity laboratory standards for NIST and LACOMET and the uncertainty budget for these standards. This report also describes the protocol for the comparison and presents the data acquired. The results are analyzed, determining the degree of equivalence between the dew/frost-point standards of NIST and LACOMET.

  12. BILATERAL KEY COMPARISON SIM.T-K6.5 ON HUMIDITY STANDARDS IN THE DEW/FROST-POINT TEMPERATURE RANGE FROM −30 °C TO +20 °C

    Science.gov (United States)

    Meyer, C.W.; Solano, A.

    2016-01-01

    A Regional Metrology Organization (RMO) Key Comparison of dew/frost point temperatures over the range −30 °C TO +20 °C was carried out by the National Institute of Standards and Technology (NIST, USA) and the Laboratorio Costarricense de Metrología (LACOMET, Costa Rica), between February 2015 and August 2015. The results of this comparison are reported here, along with descriptions of the humidity laboratory standards for NIST and LACOMET and the uncertainty budget for these standards. This report also describes the protocol for the comparison and presents the data acquired. The results are analyzed, determining the degree of equivalence between the dew/frost-point standards of NIST and LACOMET. PMID:28066029

  13. High-precision 41K/39K measurements by MC-ICP-MS indicate terrestrial variability of δ41K

    Science.gov (United States)

    Morgan, Leah; Santiago Ramos, Danielle P.; Davidheiser-Kroll, Brett; Faithfull, John; Lloyd, Nicholas S.; Ellam, Rob M.; Higgins, John A.

    2018-01-01

    Potassium is a major component in continental crust, the fourth-most abundant cation in seawater, and a key element in biological processes. Until recently, difficulties with existing analytical techniques hindered our ability to identify natural isotopic variability of potassium isotopes in terrestrial materials. However, measurement precision has greatly improved and a range of K isotopic compositions has now been demonstrated in natural samples. In this study, we present a new technique for high-precision measurement of K isotopic ratios using high-resolution, cold plasma multi-collector mass spectrometry. We apply this technique to demonstrate natural variability in the ratio of 41K to 39K in a diverse group of geological and biological samples, including silicate and evaporite minerals, seawater, and plant and animal tissues. The total range in 41K/39K ratios is ca. 2.6‰, with a long-term external reproducibility of 0.17‰ (2, N=108). Seawater and seawater-derived evaporite minerals are systematically enriched in 41K compared to silicate minerals by ca. 0.6‰, a result consistent with recent findings1, 2. Although our average bulk-silicate Earth value (-0.54‰) is indistinguishable from previously published values, we find systematic δ41K variability in some high-temperature sample suites, particularly those with evidence for the presence of fluids. The δ41K values of biological samples span a range of ca. 1.2‰ between terrestrial mammals, plants, and marine organisms. Implications of terrestrial K isotope variability for the atomic weight of K and K-based geochronology are discussed. Our results indicate that high-precision measurements of stable K isotopes, made using commercially available mass spectrometers, can provide unique insights into the chemistry of potassium in geological and biological systems. 

  14. Final report: Bilateral key comparison SIM.T-K6.3 on humidity standards in the dew/frost-point temperature range from -30°C to 20°C

    Science.gov (United States)

    Huang, Peter; Meyer, Christopher; Brionizio, Julio D.

    2015-01-01

    A Regional Metrology Organization (RMO) Key Comparison of dew/frost point temperatures was carried out by the National Institute of Standards and Technology (NIST, USA) and the Instituto Nacional de Metrologia, Qualidade e Tecnologia (INMETRO, Brazil) between October 2009 and March 2010. The results of this comparison are reported here, along with descriptions of the humidity laboratory standards for NIST and INMETRO and the uncertainty budget for these standards. This report also describes the protocol for the comparison and presents the data acquired. The results are analyzed, determining degree of equivalence between the dew/frost-point standards of NIST and INMETRO. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCT, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

  15. Zinc doped copper ferrite particles as temperature sensors for magnetic resonance imaging

    National Research Council Canada - National Science Library

    Hankiewicz, Janusz H; Alghamdi, Noweir; Hammelev, Nicholas M; Anderson, Nick R; Camley, Robert E; Stupic, Karl; Przybylski, Marek; Zukrowski, Jan; Celinski, Zbigniew J

    2017-01-01

    ...). This material has a Curie temperature near 290 K, but in the large magnetic fields found in MRI scanners, there is a significant temperature-dependent magnetic moment near body temperature; 310 K...

  16. A cryogenic analog to digital converter operating from 300 K down to 4.4 K.

    Science.gov (United States)

    Okcan, Burak; Merken, Patrick; Gielen, Georges; Van Hoof, Chris

    2010-02-01

    This paper presents a cryogenic successive approximation register (SAR) based analog to digital converter (ADC) implemented in a standard 0.35 microm complementary metal oxide semiconductor (CMOS) process. It operates from room temperature down to 4.4 K, achieving 10.47 effective number of bits (ENOB) at room temperature. At 4.4 K, the ADC achieves 8.53 ENOB at 50 kS/s sampling rate with a current consumption of 90 microA from a 3.3 V supply. The ADC utilizes an improved comparator architecture, which performs offset cancellation by using preamplifiers designed for cryogenic operation. The conventional offset cancellation algorithm is also modified in order to eliminate the effect of cryogenic anomalies below freeze-out temperature. The power efficiency is significantly improved compared to the state of the art semiconductor ADCs operating in the same temperature range.

  17. Nitrosyl hemoglobins: EPR above 80 K

    Energy Technology Data Exchange (ETDEWEB)

    Wajnberg, E.; Bemski, G.; El-Jaick, L.J.; Alves, O.C.

    1995-03-01

    The EPR spectra of nitrosyl hemoglobin and myoglobin in different conditions (native, denatured and lyophilized), as well as of hematin-NO were obtained in the temperature range of 80 K-280 K. There is a substantial and reversible.decrease of the areas of the EPR spectra of all the hemoglobin samples above 150 K. The interpretation of the results implies the existence of two conformational states in thermal equilibrium only one of which is EPR detectable. Thermodynamical parameters are determined for the hexa and penta-coordinated cases. (author). 25 refs, 3 figs.

  18. Vitamine K

    Directory of Open Access Journals (Sweden)

    Bal dit Sollier Claire

    2011-03-01

    Full Text Available Subclasses of vitamin K, their origins, their differential characteristics of absorption and metabolism, their relative effects on gammacarboxylation of various proteins implicated in hemostasis andcoagulation, in bone calcification are not well known even by experts in these fields. These misunderstandings explain errors in recommendations for public and for patients. This review will not expose again the fundamentals on vitamins K as presented in the paper by Marc Guillaumont published in 2000 in this same journal. This 2011 review will try to update our actual knowledge and most of all will insist on their practical implications especially on the management of oral anticoagulant treatments since until recently vitamin K antagonist was the only available type of such a treatment. Several examples illustrate the need for a better understanding of this subject. The fear that diet vitamin K could deregulate the equilibrium of oral vitamin K antagonist treatment leads to recommend a quite total suppression of vitamin K containing components in the diet of anticoagulated patients. This leads to an opposite effect: a high sensitivity to vitamin K and to disequilibrium of the anticoagulant treatment while a comprehensivemoderate and regular diet intake of vitamin K first facilitates the food choice of the patients but also helps to stabilise the treatment of chronically anticoagulated patients. Vitamin K plays a role in bone calcification and in osteoporosis prevention. Until recently the food supplementation with vitamin K in view of preventing osteoporosis in general population was strongly limited due to fear to affect the treatment equilibrium in anticoagulated patients. While an understanding that the effects of moderate supplementation in vitamin K has no or limited effect on anticoagulation and on the long run could at the opposite help to stabilize the daily level of anticoagulation in patients chronically treated with vitamin K.

  19. R K Bhowmik

    Indian Academy of Sciences (India)

    Hybrid recoil mass analyzer at IUAC – First results using gas-filled mode and future plans · N Madhavan S Nath T Varughese J Gehlot A Jhingan P Sugathan A K Sinha R Singh K M Varier M C Radhakrishna E Prasad S Kalkal G Mohanto J J Das Rakesh Kumar R P Singh S Muralithar R K Bhowmik A Roy Rajesh Kumar ...

  20. K sup + - scattering

    CERN Document Server

    Farhan, A M

    2002-01-01

    A prescription is given to construct an effective interaction that may describe the scattering of K sup + by spin-zero nuclei in a more reliable way. This prescription is based on the Lorentz invariant representation of the meson-nucleon amplitude and the use of the Klein-Gordon equation of motion. Good results for K sup + - sup 1 sup 2 C as well as K sup + - D total cross sections at various energies have been obtained. (author)

  1. Temperature measurement

    Science.gov (United States)

    ... an oral temperature. Other factors to take into account are: In general, rectal temperatures are considered to ... urac.org). URAC's accreditation program is an independent audit to verify that A.D.A.M. follows ...

  2. Socool: A 300 K-0.3 K pulse tube/sorption cooler

    Science.gov (United States)

    Duband, L.; Clerc, L.; Ravex, A.

    2002-05-01

    CEA/SBT has acquired substantial experience in the fields of Pulse Tube (PTC) and Sorption coolers. Double stage PTC capable of lifting about 0.5 W of cooling power at 4 K have been successfully experimented in the past years. Single stage 3He and 4He sorption coolers have been developed for both ground and space applications. A precooling temperature below 2.5 K is required to operate a 3He sorption cooler efficiently. This is commonly achieved with a pumped liquid 4He bath. However for some applications (for example bolometers cooling in astrophysics) the vibrations induced by the pumping system are problematic. In addition the fraction of liquid lost during the bath pumped down significantly affects the bath hold time. To overcome this difficulty, a double stage (4He/3He) sorption cooler has been developed which can be operated either from an atmospheric 4He bath or from a 4 K PTC, and which provides temperature down to 260 mK. The first experimental results obtained with this cooler and a 4 K PTC developed at CEA-SBT were excellent and has lead us to develop this cooler with a commercial 4 K PTC. This paper presents the performance obtained with a double stage sorption cooler using a 4 K CRYOMECH PT405 Pulse tube. This new cooler concept is the first cryogen free system covering the range 300 K-300 mK. This technology has been transferred to Air Liquide for industrial manufacturing and commercialization.

  3. P. K. Manoharan

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Astrophysics and Astronomy. P. K. Manoharan. Articles written in Journal of Astrophysics and Astronomy. Volume 27 Issue 2-3 June-September 2006 pp 151-157 Oral Presentations. North–South Distribution of Solar Flares during Cycle 23 · Bhuwan Joshi P. Pant P. K. Manoharan · More Details ...

  4. Parallel k-means++

    Energy Technology Data Exchange (ETDEWEB)

    2017-04-04

    A parallelization of the k-means++ seed selection algorithm on three distinct hardware platforms: GPU, multicore CPU, and multithreaded architecture. K-means++ was developed by David Arthur and Sergei Vassilvitskii in 2007 as an extension of the k-means data clustering technique. These algorithms allow people to cluster multidimensional data, by attempting to minimize the mean distance of data points within a cluster. K-means++ improved upon traditional k-means by using a more intelligent approach to selecting the initial seeds for the clustering process. While k-means++ has become a popular alternative to traditional k-means clustering, little work has been done to parallelize this technique. We have developed original C++ code for parallelizing the algorithm on three unique hardware architectures: GPU using NVidia's CUDA/Thrust framework, multicore CPU using OpenMP, and the Cray XMT multithreaded architecture. By parallelizing the process for these platforms, we are able to perform k-means++ clustering much more quickly than it could be done before.

  5. Jayanta K Bhattacharjee

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education. Jayanta K Bhattacharjee. Articles written in Resonance – Journal of Science Education. Volume 6 Issue 9 September 2001 pp 19-34 General Article. Entropy à la Boltzmann · Jayanta K Bhattacharjee · More Details Fulltext PDF ...

  6. S K Bhattacharjee

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education. S K Bhattacharjee. Articles written in Resonance – Journal of Science Education. Volume 12 Issue 9 September 2007 pp 80-82 Book Review. The Essential Microbe · S K Bhattacharjee · More Details Fulltext PDF ...

  7. V K Agarwal

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Earth System Science. V K Agarwal. Articles written in Journal of Earth System Science. Volume 118 Issue 4 August 2009 pp 331-343. Polarized microwave forward model simulations for tropical storm Fanoos · C Balaji M Deiveegan S P Venkateshan R M Gairola A Sarkar V K Agarwal.

  8. K VijayRaghavan

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education. K VijayRaghavan. Articles written in Resonance – Journal of Science Education. Volume 8 Issue 11 November 2003 pp 5-7 Article-in-a-Box. Thomas Hunt Morgan and Developmental Biology · K VijayRaghavan · More Details Fulltext PDF. Volume 13 Issue 10 ...

  9. K S Valdiya

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education. K S Valdiya. Articles written in Resonance – Journal of Science Education. Volume 1 Issue 5 May 1996 pp 19-28 General Article. River Piracy Saraswati that Disappeared · K S Valdiya · More Details Fulltext PDF. Volume 1 Issue 8 August 1996 pp 55-63 General ...

  10. K D Gharde

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Earth System Science. K D Gharde. Articles written in Journal of Earth System Science. Volume 124 Issue 5 July 2015 pp 933-943. Application of ANN and fuzzy logic algorithms for streamflow modelling of Savitri catchment · Mahesh Kothari K D Gharde · More Details Abstract Fulltext PDF.

  11. anup k talukdar

    Indian Academy of Sciences (India)

    Home; Journals; Bulletin of Materials Science. ANUP K TALUKDAR. Articles written in Bulletin of Materials Science. Volume 40 Issue 7 December 2017 pp 1301-1308. A study on the synthesis, characterization and catalytic activity of ruthenium-substituted MFI (Mobil Five) zeolite · KISHOR KR SHAH ANUP K TALUKDAR.

  12. S K Golam Ali

    Indian Academy of Sciences (India)

    Home; Journals; Pramana – Journal of Physics. S K Golam Ali. Articles written in Pramana – Journal of Physics. Volume 72 Issue 2 February 2009 pp 445-450 Brief Reports. Effects of three-body atomic interaction and optical lattice on solitons in quasi-one-dimensional Bose–Einstein condensate · S K Golam Ali B Talukdar ...

  13. T K Umesh

    Indian Academy of Sciences (India)

    Home; Journals; Pramana – Journal of Physics. T K Umesh. Articles written in Pramana – Journal of Physics. Volume 58 Issue 1 January 2002 pp 31-38 Research Articles. X-ray fluorescence in some rare earth and high elements excited by 661.6 keV -rays · T Yashoda S Krishnaveni Shivalinge Gowda T K Umesh ...

  14. P K Basu

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education. P K Basu. Articles written in Resonance – Journal of Science Education. Volume 5 Issue 7 July 2000 pp 100-104 Information and Announcements. Insititute of Radio Physics and Electronics · P K Basu · More Details Fulltext PDF. Volume 7 Issue 7 July 2002 pp ...

  15. P K SAHU

    Indian Academy of Sciences (India)

    Home; Journals; Sadhana. P K SAHU. Articles written in Sadhana. Volume 41 Issue 5 May 2016 pp 469-477. An improved method for R-peak detection by using Shannon energy envelope · M RAKSHIT D PANIGRAHY P K SAHU · More Details Abstract Fulltext PDF. R-peaks in electrocardiogram (ECG) play a vital role in ...

  16. P K Thiruvikraman

    Indian Academy of Sciences (India)

    Home; Journals; Sadhana. P K Thiruvikraman. Articles written in Sadhana. Volume 37 Issue 6 December 2012 pp 739-745. Automated image enhancement using power law transformations · S P Vimal P K Thiruvikraman · More Details Abstract Fulltext PDF. We propose a scheme for automating power law transformations ...

  17. P K Srivastava

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education. P K Srivastava. Articles written in Resonance – Journal of Science Education. Volume 12 Issue 8 August 2007 pp 85-96 Reflections. Remembering Newton · P K Srivastava · More Details Fulltext PDF ...

  18. P K Bajpai

    Indian Academy of Sciences (India)

    Home; Journals; Bulletin of Materials Science. P K Bajpai. Articles written in Bulletin of Materials Science. Volume 26 Issue 5 August 2003 pp 461-464 Sensor Materials. Preparation, characterization and dielectric behaviour of some yttrium doped strontium stannates · P K Bajpai Kuldeep Ratre Mukul Pastor T P Sinha.

  19. P K Sen

    Indian Academy of Sciences (India)

    Home; Journals; Sadhana. P K Sen. Articles written in Sadhana. Volume 25 Issue 5 October 2000 pp 423-437. Behaviour of organised disturbances in fully developed turbulent channel flow · P K Sen Srinivas V Veeravali · More Details Abstract Fulltext PDF. In our earlier work we have shown the relevance of stability theory ...

  20. P K Karmakar

    Indian Academy of Sciences (India)

    Home; Journals; Pramana – Journal of Physics. P K Karmakar. Articles written in Pramana – Journal of Physics. Volume 68 Issue 4 April 2007 pp 631-648 Research Articles. Application of inertia-induced excitation theory for nonlinear acoustic modes in colloidal plasma equilibrium flow · P K Karmakar · More Details ...

  1. Pravin K Bhadane

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education. Pravin K Bhadane. Articles written in Resonance – Journal of Science Education. Volume 4 Issue 2 February 1999 pp 8-19 Series Article. Electrostatics in Chemistry - Basic Principles · Shridhar R Gadre Pravin K Bhadane · More Details Fulltext PDF. Volume 4 ...

  2. K J Jarag

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education. K J Jarag. Articles written in Resonance – Journal of Science Education. Volume 15 Issue 9 September 2010 pp 804-818 General Article. Laser Dyes · G S Shankarling K J Jarag · More Details Fulltext PDF ...

  3. K T Kashyap

    Indian Academy of Sciences (India)

    Home; Journals; Bulletin of Materials Science. K T Kashyap. Articles written in Bulletin of Materials Science. Volume 23 Issue 1 February 2000 pp 39-45 Metallic Materials. Role of diffusional coherency strain theory in the discontinuous precipitation in Mg–Al alloy · K T Kashyap C Ramachandra M Sujatha B Chatterji.

  4. A K Singh

    Indian Academy of Sciences (India)

    Characteristics of low latitude ionospheric E-region irregularities linked with daytime VHF scintillations measured from Varanasi · K Patel A K Singh R P Patel R P Singh · More Details Abstract Fulltext PDF. VHF amplitude scintillations recorded during the daytime period from January 1991 to December 1993, April 1998 to ...

  5. K R Rao

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education. K R Rao. Articles written in Resonance – Journal of Science Education. Volume 2 Issue 6 June 1997 pp 54-59 General Article. The Liquid State - The Arrangement of Atoms · K R Rao · More Details Fulltext PDF. Volume 2 Issue 8 August 1997 pp 26-31 General ...

  6. K J RAO

    Indian Academy of Sciences (India)

    Home; Journals; Bulletin of Materials Science. K J RAO. Articles written in Bulletin of Materials Science. Volume 23 Issue 6 December 2000 pp 461-466 Material Synthesis. Microwave synthesis of electrode materials for lithium batteries · M Harish Bhat B P Chakravarthy P A Ramakrishnan A Levasseur K J RAO.

  7. A J K Prasad

    Indian Academy of Sciences (India)

    Home; Journals; Bulletin of Materials Science. A J K Prasad. Articles written in Bulletin of Materials Science. Volume 34 Issue 7 December 2011 pp 1339-1344. Synthesis and characterization of mixture of nanozirconia and nanosilica obtained from commercially available zircon flour by sol–gel method · A J K Prasad S M ...

  8. k palani kumar

    Indian Academy of Sciences (India)

    Home; Journals; Bulletin of Materials Science. K PALANI KUMAR. Articles written in Bulletin of Materials Science. Volume 40 Issue 1 February 2017 pp 117-128. Investigation on mechanical properties of woven alovera/sisal/kenaf fibres and their hybrid composites · K PALANI KUMAR A SHADRACH JEYA SEKARAN K ...

  9. Swagato K Ray

    Indian Academy of Sciences (India)

    Home; Journals; Proceedings – Mathematical Sciences. Swagato K Ray. Articles written in Proceedings – Mathematical Sciences. Volume 114 Issue 2 May 2004 pp 159-180. Cowling–Price Theorem and Characterization of Heat Kernel on Symmetric Spaces · Swagato K Ray Rudra P Sarkar · More Details Abstract Fulltext ...

  10. K Krishna Kishore

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Chemical Sciences. K Krishna Kishore. Articles written in Journal of Chemical Sciences. Volume 113 Issue 4 August 2001 pp 351-359 Physical and Theoretical. Mechanism of oxidation of L-methionine by iron(III)-1,10-phenanthroline complex - A kinetic study · P Vani K Krishna Kishore R ...

  11. e(+)e(-)-> K+K-pi(+)pi(-), K+K-pi(0)pi(0) and K+K-K+K- cross sections measured with initial-state radiation

    NARCIS (Netherlands)

    Aubert, B.; Zhang, L.L.; Chen, S.; Wang, W.; Anderson, J.M.; Li, X.H.; Baak, M.A.; Raven, G.; Snoek, H.; David, P.; Schroder, H.; Liu, H.; van Bakel, N.; Wagner, A.; Yu, Z.

    2007-01-01

    We study the processes e+e-→K+K-π+π-γ, K+K-π0π0γ and K+K-K+K-γ, where the photon is radiated from the initial state. About 34600, 4400 and 2300 fully reconstructed events, respectively, are selected from 232fb-1 of BABAR data. The invariant mass of the hadronic final state defines the effective e+e-

  12. The Kelvin and Temperature Measurements

    Science.gov (United States)

    Mangum, B. W.; Furukawa, G. T.; Kreider, K. G.; Meyer, C. W.; Ripple, D. C.; Strouse, G. F.; Tew, W. L.; Moldover, M. R.; Johnson, B. Carol; Yoon, H. W.; Gibson, C. E.; Saunders, R. D.

    2001-01-01

    The International Temperature Scale of 1990 (ITS-90) is defined from 0.65 K upwards to the highest temperature measurable by spectral radiation thermometry, the radiation thermometry being based on the Planck radiation law. When it was developed, the ITS-90 represented thermodynamic temperatures as closely as possible. Part I of this paper describes the realization of contact thermometry up to 1234.93 K, the temperature range in which the ITS-90 is defined in terms of calibration of thermometers at 15 fixed points and vapor pressure/temperature relations which are phase equilibrium states of pure substances. The realization is accomplished by using fixed-point devices, containing samples of the highest available purity, and suitable temperature-controlled environments. All components are constructed to achieve the defining equilibrium states of the samples for the calibration of thermometers. The high quality of the temperature realization and measurements is well documented. Various research efforts are described, including research to improve the uncertainty in thermodynamic temperatures by measuring the velocity of sound in gas up to 800 K, research in applying noise thermometry techniques, and research on thermocouples. Thermometer calibration services and high-purity samples and devices suitable for “on-site” thermometer calibration that are available to the thermometry community are described. Part II of the paper describes the realization of temperature above 1234.93 K for which the ITS-90 is defined in terms of the calibration of spectroradiometers using reference blackbody sources that are at the temperature of the equilibrium liquid-solid phase transition of pure silver, gold, or copper. The realization of temperature from absolute spectral or total radiometry over the temperature range from about 60 K to 3000 K is also described. The dissemination of the temperature scale using radiation thermometry from NIST to the customer is achieved by

  13. The Kelvin and Temperature Measurements.

    Science.gov (United States)

    Mangum, B W; Furukawa, G T; Kreider, K G; Meyer, C W; Ripple, D C; Strouse, G F; Tew, W L; Moldover, M R; Johnson, B C; Yoon, H W; Gibson, C E; Saunders, R D

    2001-01-01

    The International Temperature Scale of 1990 (ITS-90) is defined from 0.65 K upwards to the highest temperature measurable by spectral radiation thermometry, the radiation thermometry being based on the Planck radiation law. When it was developed, the ITS-90 represented thermodynamic temperatures as closely as possible. Part I of this paper describes the realization of contact thermometry up to 1234.93 K, the temperature range in which the ITS-90 is defined in terms of calibration of thermometers at 15 fixed points and vapor pressure/temperature relations which are phase equilibrium states of pure substances. The realization is accomplished by using fixed-point devices, containing samples of the highest available purity, and suitable temperature-controlled environments. All components are constructed to achieve the defining equilibrium states of the samples for the calibration of thermometers. The high quality of the temperature realization and measurements is well documented. Various research efforts are described, including research to improve the uncertainty in thermodynamic temperatures by measuring the velocity of sound in gas up to 800 K, research in applying noise thermometry techniques, and research on thermocouples. Thermometer calibration services and high-purity samples and devices suitable for "on-site" thermometer calibration that are available to the thermometry community are described. Part II of the paper describes the realization of temperature above 1234.93 K for which the ITS-90 is defined in terms of the calibration of spectroradiometers using reference blackbody sources that are at the temperature of the equilibrium liquid-solid phase transition of pure silver, gold, or copper. The realization of temperature from absolute spectral or total radiometry over the temperature range from about 60 K to 3000 K is also described. The dissemination of the temperature scale using radiation thermometry from NIST to the customer is achieved by calibration of

  14. Cryogen free cooling of ASTRO-H SXS Helium Dewar from 300 K to 4 K

    Science.gov (United States)

    Kanao, Ken'ichi; Yoshida, Seiji; Miyaoka, Mikio; Tsunematsu, Shoji; Otsuka, Kiyomi; Hoshika, Shunji; Narasaki, Katsuhiro; Mitsuda, Kazuhisa; Yamasaki, Noriko; Takei, Yoh; Fujimoto, Ryuji; Sato, Yoichi; Okamoto, Atsushi; Noda, Hirofumi; DiPirro, Michel J.; Shirron, Peter J.

    2017-12-01

    Soft X-ray Spectrometer instrument (SXS) is one of the primary scientific instruments of ASTRO-H. SXS has a cold detector that is cooled to 50 mK by using a multi-stage Adiabatic Demagnetization Refrigerator (ADR). SXS Dewar containing ADR provides 1.3 K heat sink by using liquid helium in nominal operation. After liquid helium is dried up, 4 K heat sink is provided by using mechanical coolers. Both nominal operation and cryogen free operation were successfully demonstrated. This paper describes the test result of cryogen free operation and cool-down performance from room temperature by using only mechanical coolers without liquid helium. The coolers on the Dewar cooled down cold mass from around 300 K to 4 K with 260 W electric power in 40 days. Cold mass is 35 kg in 4 K area including the helium tank, ADR and detector assembly.

  15. Temperature dependence of fission product release rates

    Energy Technology Data Exchange (ETDEWEB)

    Kelly, J.L.; McGown, M.E.; Reynolds, A.B.

    1984-10-01

    Fission product fractional release rates, K, used in the Albrecht-Wild model and measured at Kernforschungszentrum Karlsruhe and Oak Ridge National Laboratory can be fitted well by a single straight line for each fission product over the entire temperature range of the data when in K is plotted as a function of 1/T. Past applications of the Albrecht-Wild model have used plots of ln K versus T, which required three fits over the temperature range. Thus it is suggested that fractional release rates be represented by the Arrhenius form, K = K /SUB o/ exp(-Q/RT).

  16. Excess enthalpies of the ternary mixtures: {l_brace}tetrahydrofuran + 3-methylpentane + (octane or decane){r_brace} at the temperature 298.15 K[Excess enthalpy; Ternary mixture; Tetrahydrofuran; 3-Methylpentane; n-Octane; n-Decane; Liebermann-Fried model

    Energy Technology Data Exchange (ETDEWEB)

    Wang Zhaohui; Benson, George C. E-mail: gbenson@eng.uottawa.ca; Lu, Benjamin C.-Y

    2003-10-01

    Measurements of excess molar enthalpies at the temperature 298.15 K in a flow microcalorimeter, are reported for the two ternary mixtures {l_brace}X{sub 1}C{sub 4}H{sub 8}O + X{sub 2}CH{sub 3}CH{sub 2}CH(CH{sub 3})CH{sub 2}CH{sub 3} + (1-X{sub 1}-X{sub 2})CH{sub 3}(CH{sub 2}){sub v-2}CH{sub 3}{r_brace} with v=8 and 10. Smooth representations of the results are described and used to construct constant-enthalpy contours on Roozeboom diagrams. It is shown that useful estimates of the ternary enthalpies can be obtained from the Liebermann-Fried model, using only the physical properties of the components and their binary mixtures.

  17. Temperature dependence of alkali-antimonide photocathodes: Evaluation at cryogenic temperatures

    Science.gov (United States)

    Mamun, M. A.; Hernandez-Flores, M. R.; Morales, E.; Hernandez-Garcia, C.; Poelker, M.

    2017-10-01

    CsxKySb photocathodes were manufactured on a niobium substrate and evaluated over a range of temperatures from 300 to 77 K. Vacuum conditions were identified that minimize surface contamination due to gas adsorption when samples were cooled below room temperature. Measurements of the photocathode spectral response provided a means to evaluate the photocathode band gap dependence on the temperature and to predict the photocathode quantum efficiency at 4 K, a typical temperature at which superconducting radio frequency photoguns operate.

  18. Couleurs, etoiles, temperatures.

    Science.gov (United States)

    Spite, F.

    The eye is able to distinguish very tiny color differences of contiguous objects (at high light level, cones vision), but it is not a reliable colorimeter. Hot objects (a heated iron rod) emits some red light, a hotter object would provide a yellow-orange light (the filament of a bulb) and a still hotter one a white or even bluish light : this may be at reverse of common life codes, where "red" means hot water and/or danger, and "blue" cool water or cool air. Stars are a good illustration of the link between temperatures and colors. A heated iron rod has a temperature of about 800 K. Let us recall that K is a temperature unit (Kelvin) such that the Kelvin temperature is the Celsius temperature +273).The so called red stars (or cool stars) have temperature around 3000 K, higher than "white-hot iron". The Sun has a still higher temperature (5800 K) and its color is white : the solar light is by definition the "white light", and includes violet, blue, green, yellow, orange and red colors in balanced proportions (the maximum in the yellow-green). It is often said that the Sun is a yellow star. Admittedly, a brief glimpse at the Sun (take care ! never more than a VERY brief glimpse !) provides a perception of yellow light, but such a vision, with the eye overwhelmed by a fierce light, is not able to provide a good evaluation of the solar color : prefer a white sheet of paper illuminated by the Sun at noon and conclude that "the Sun is a white star". It is sometimes asked why red, white and bluish stars are seen in the sky, but no green stars : the solar light has its maximum intensity in the green, but such a dominant green light, equilibrated by some blue and some red light, is what we call "white", so that stars similar to the Sun, with a maximum in the green, are seen as white stars. Faint stars (rods vision of the eye) are also seen as white stars. Spots on the Sun (never look at the Sun ! let us say spots on "projected images of the Sun") appear as black spots

  19. Laev pooleks / K. Heinmaa

    Index Scriptorium Estoniae

    Heinmaa, K.

    1982-01-01

    Melassi vedanud tanker murdus tormis pooleks, nende omavaheline kaugus oli lõpuks u 100 miili. Hukkus üks inimene, laeva pooled pukseeriti sadamasse kuid otsustati maha kanda, kätte saadi osa melassist

  20. DNR 100K Hydrography

    Data.gov (United States)

    Minnesota Department of Natural Resources — Polygons representing hydrographic features originating from the USGS 1:100,000 (100K)DLG (Digital Line Graph) dataset. The data have been converted into ArcView and...

  1. K Basin safety analysis

    Energy Technology Data Exchange (ETDEWEB)

    Porten, D.R.; Crowe, R.D.

    1994-12-16

    The purpose of this accident safety analysis is to document in detail, analyses whose results were reported in summary form in the K Basins Safety Analysis Report WHC-SD-SNF-SAR-001. The safety analysis addressed the potential for release of radioactive and non-radioactive hazardous material located in the K Basins and their supporting facilities. The safety analysis covers the hazards associated with normal K Basin fuel storage and handling operations, fuel encapsulation, sludge encapsulation, and canister clean-up and disposal. After a review of the Criticality Safety Evaluation of the K Basin activities, the following postulated events were evaluated: Crane failure and casks dropped into loadout pit; Design basis earthquake; Hypothetical loss of basin water accident analysis; Combustion of uranium fuel following dryout; Crane failure and cask dropped onto floor of transfer area; Spent ion exchange shipment for burial; Hydrogen deflagration in ion exchange modules and filters; Release of Chlorine; Power availability and reliability; and Ashfall.

  2. DNR 24K Lakes

    Data.gov (United States)

    Minnesota Department of Natural Resources — Medium scale lake polygons derived from the National Wetlands Inventory (NWI) polygons and MnDOT Basemap lake delineations. Integrated with the DNR 24K Streams...

  3. (Liquid + liquid) equilibria of (sulfolane + benzene + n-hexane), (N-formylmorpholine + benzene + n-hexane), and (sulfolane + N-formylmorpholine + benzene + n-hexane) at temperatures ranging from (298.15 to 318.15) K: Experimental results and correlation

    Energy Technology Data Exchange (ETDEWEB)

    Mahmoudi, Jafar [School of Chemical, Gas and Petroleum Engineering, Semnan University, Semnan 35195-363 (Iran, Islamic Republic of); Lotfollahi, Mohammad Nader, E-mail: mnlotfollahi@semnan.ac.i [School of Chemical, Gas and Petroleum Engineering, Semnan University, Semnan 35195-363 (Iran, Islamic Republic of)

    2010-04-15

    The experimental (liquid + liquid) equilibrium (LLE) properties for two ternary systems containing (N-formylmorpholine + benzene + n-hexane), (sulfolane + benzene + n-hexane) and a quaternary mixed solvent system (sulfolane + N-formylmorpholine + benzene + n-hexane) were measured at temperature ranging from (298.15 to 318.15) K and at an atmospheric pressure. The experimental distribution coefficients and selectivity factors are presented to evaluate the efficiency of the solvents for extraction of benzene from n-hexane. The LLE results obtained indicate that increasing temperature decreases selectivity for all solvents. The LLE results for the systems studied were used to obtain binary interaction parameters in the UNIQUAC model by minimizing the root mean square deviations (RMSD) between the experimental and calculated results. Using the interaction parameters obtained, the phase equilibria in the systems were calculated and plotted. The calculated compositions based on the UNIQUAC model were found to be in good agreement with the experimental values. The result of the RMSD obtained by comparing the calculated and experimental two-phase compositions is 0.0163 for (N-formylmorpholine + benzene + n-hexane) system and is 0.0120 for (sulfolane + benzene + n-hexane) system.

  4. P K Sahu

    Indian Academy of Sciences (India)

    Home; Journals; Pramana – Journal of Physics. P K Sahu. Articles written in Pramana – Journal of Physics. Volume 60 Issue 5 May 2003 pp 1107-1111. Systematics of elliptic flow in heavy-ion collisions · P K Sahu N Otuka A Ohnishi M Baldo · More Details Abstract Fulltext PDF. We analyze elliptic flow from SIS to RHIC ...

  5. Eske K. Mathiesen

    DEFF Research Database (Denmark)

    Skiveren, Tobias; Gregersen, Martin

    I monografien tegner Martin Gregersen og Tobias Skiveren et portræt af Eske K. Mathiesens særegne forfattervirke gennem en tæt sammenvævning af humorfilosofi, økokritiske perspektiver og kritisk teori.......I monografien tegner Martin Gregersen og Tobias Skiveren et portræt af Eske K. Mathiesens særegne forfattervirke gennem en tæt sammenvævning af humorfilosofi, økokritiske perspektiver og kritisk teori....

  6. K2-99

    DEFF Research Database (Denmark)

    Smith, A. M. S.; Gandolfi, D.; Barragan, O.

    2017-01-01

    We report the discovery from K2 of a transiting planet in an 18.25-d, eccentric (0.19 +/- 0.04) orbit around K2-99, an 11th magnitude subgiant in Virgo. We confirm the planetary nature of the companion with radial velocities, and determine that the star is a metal-rich ([ Fe/H] = 0.20 +/- 0...... in the system, perhaps a brown dwarf orbiting with a period of several hundred days....

  7. Analysis of D0 -> K anti-K X Decays

    Energy Technology Data Exchange (ETDEWEB)

    Jessop, Colin P.

    2003-06-06

    Using data taken with the CLEO II detector, they have studied the decays of the D{sup 0} to K{sup +}K{sup -}, K{sup 0}{bar K}{sup 0}, K{sub S}{sup 0}K{sub S}{sup 0}, K{sub S}{sup 0}K{sub S}{sup 0}{pi}{sup 0}, K{sup +}K{sup -}{pi}{sup 0}. The authors present significantly improved results for B(D{sup 0} {yields} K{sup +}K{sup -}) = (0.454 {+-} 0.028 {+-} 0.035)%, B(D{sup 0} {yields} K{sup 0}{bar K}{sup 0}) = (0.054 {+-} 0.012 {+-} 0.010)% and B(D{sup 0} {yields} K{sub S}{sup 0}K{sub S}{sup 0}K{sub S}{sup 0}) = (0.074 {+-} 0.010 {+-} 0.015)% where the first errors are statistical and the second errors are the estimate of their systematic uncertainty. They also present a new upper limit B(D{sup 0} {yields} K{sub S}{sup 0}K{sub S}{sup 0}{pi}{sup 0}) < 0.059% at the 90% confidence level and the first measurement of B(D{sup 0} {yields} K{sup +}K{sup -}{pi}{sup 0}) = (0.14 {+-} 0.04)%.

  8. Low-temperature tracking detectors

    CERN Document Server

    Niinikoski, T O; Anbinderis, P; Anbinderis, T; D'Ambrosio, N; de Boer, Wim; Borchi, E; Borer, K; Bruzzi, M; Buontempo, S; Chen, W; Cindro, V; Dezillie, B; Dierlamm, A; Eremin, V; Gaubas, E; Gorbatenko, V; Granata, V; Grigoriev, E; Grohmann, S; Hauler, F; Heijne, Erik H M; Heising, S; Hempel, O; Herzog, R; Härkönen, J; Ilyashenko, Yu S; Janos, S; Jungermann, L; Kalesinskas, V; Kapturauskas, J; Laiho, R; Li, Z; Luukka, Panja; Mandic, I; De Masi, R; Menichelli, D; Mikuz, M; Militaru, O; Nüssle, G; O'Shea, V; Pagano, S; Paul, S; Perea-Solano, B; Piotrzkowski, K; Pirollo, S; Pretzl, K; Rahman, M; Rato-Mendes, P; Rouby, X; Ruggiero, G; Smith, K; Sousa, P; Tuominen, E; Tuovinen, E; Vaitkus, J; Verbitskaya, E; Da Vià, C; Vlasenko, L; Vlasenko, M; Wobst, E; Zavrtanik, M

    2004-01-01

    RD39 collaboration develops new detector techniques for particle trackers, which have to withstand fluences up to 10/sup 16/ cm/sup -2 / of high-energy particles. The work focuses on the optimization of silicon detectors and their readout electronics while keeping the temperature as a free parameter. Our results so far suggest that the best operating temperature is around 130 K. We shall also describe in this paper how the current-injected mode of operation reduces the polarization of the bulk silicon at low temperatures, and how the engineering and materials problems related with vacuum and low temperature can be solved. (9 refs).

  9. matK

    Science.gov (United States)

    More, Ravi Prabhakar; Mane, Rupali Chandrashekhar; Purohit, Hemant J

    2016-01-01

    DNA barcoding is widely used and most efficient approach that facilitates rapid and accurate identification of plant species based on the short standardized segment of the genome. The nucleotide sequences of maturaseK ( matK ) and ribulose-1, 5-bisphosphate carboxylase ( rbcL ) marker loci are commonly used in plant species identification. Here, we present a new and highly efficient approach for identifying a unique set of discriminating nucleotide patterns to generate a signature (i.e. regular expression) for plant species identification. In order to generate molecular signatures, we used matK and rbcL loci datasets, which encompass 125 plant species in 52 genera reported by the CBOL plant working group. Initially, we performed Multiple Sequence Alignment (MSA) of all species followed by Position Specific Scoring Matrix (PSSM) for both loci to achieve a percentage of discrimination among species. Further, we detected Discriminating Patterns (DP) at genus and species level using PSSM for the matK dataset. Combining DP and consecutive pattern distances, we generated molecular signatures for each species. Finally, we performed a comparative assessment of these signatures with the existing methods including BLASTn, Support Vector Machines (SVM), Jrip-RIPPER, J48 (C4.5 algorithm), and the Naïve Bayes (NB) methods against NCBI-GenBank matK dataset. Due to the higher discrimination success obtained with the matK as compared to the rbcL , we selected matK gene for signature generation. We generated signatures for 60 species based on identified discriminating patterns at genus and species level. Our comparative assessment results suggest that a total of 46 out of 60 species could be correctly identified using generated signatures, followed by BLASTn (34 species), SVM (18 species), C4.5 (7 species), NB (4 species) and RIPPER (3 species) methods As a final outcome of this study, we converted signatures into QR codes and developed a software matK -QR Classifier (http

  10. Progress Toward a Compact 0.05 K Magnet Refrigerator Operating from 10 K

    Science.gov (United States)

    Canavan, Edgar; Shirron, Peter; DiPirro, Micheal; Tuttle, James; Jackson, Michael; King, Todd; Numazawa, Takenori

    2003-01-01

    Much of the most interesting information regarding our universe is hidden in the sub-millimeter, infrared, and x-rays bands of the spectrum, to which our atmosphere is largely opaque. Thus, missions exploring these bands are a very important part of NASA s Space Science program. Coincidentally, the most sensitive detectors in these spectral regions operate at extremely low temperatures, typically 0.05 - 0.10 K. Generally these temperatures will be achieved using magnetic refrigerators, also know as Adiabatic Demagnetization Refrigerators, or ADRs. Current ADRs, such as the one used in the XRS-II instrument on the Astro-E2 satellite, use a single-stage to cool detectors from 1.3 K to 0.06 K. The ADR is designed so that it can absorb the heat on the detector stage for at least 24 hours before it must stop, warm up to the helium bath temperature (1.3 K), and dump the accumulated heat. Future detector arrays will be much larger and will have higher heat dissipation. Furthermore, future missions will use mechanical cryocoolers to provide upper stage cooling, but they can only reach 4 - 10 K. Trying to scale heavy (-15 kg) single stage ADRs up to the higher heat loads and higher heat rejection temperatures required leads to unacceptably large systems. The GSFC Cryogenics Branch has developed the Continuous ADR (CADR) to solve this problem. The CADR consists of a series of ADR stages that sequentially pass heat from the load up to the high temperature heat sink. The stage connected to the load remains at a constant temperature. The continuous stage effectively decouples detector operation from ADR operation, allowing the ADR stages to be cycled much more rapidly. Rapid cycling leads to higher cooling power density. The cascading, multistage arrangement allows the magnetic refrigerant of each stage to be optimized for its own temperature swing. In the past year, we have made good progress toward a 0.05 to 10K system. A four-stage system that operates from 4.2 K was

  11. Thermal Conductivity of Manganin Between 10 mK and 54 mK

    Science.gov (United States)

    Ventura, Guglielmo; Giomi, Silvia

    2017-09-01

    The thermal conductivity of Manganin (Cu 86 %, Ni 2 %, Mn 12 %) in the range 10-50 mK was measured by means of a new method that uses a metal-insulator junction (M-I.J) of known characteristics to read temperatures at one end of the sample. The same power P that crosses the sample to measure its thermal resistance flows through the M-I.J. A suitable choice of the M-I.J allows the temperature T of the upper end of the sample to rise above 20 mK. T was measured by a small size Ruthenium thermometer.

  12. Controllable solvothermal synthesis and photocatalytic properties of complex (oxy)fluorides K2TiOF4, K3TiOF5, K7Ti4O4F7 and K2TiF6.

    Science.gov (United States)

    Sheng, Jie; Tang, Kaibin; Cheng, Wei; Wang, Junli; Nie, Yanxiang; Yang, Qing

    2009-11-15

    Complex (oxy)fluorides K(2)TiF(6), K(2)TiOF(4), K(3)TiOF(5) and K(7)Ti(4)O(4)F(7) have been successfully synthesized for the first time through a controllable solvothermal route involving different solvents, for example, methanol, methanol-H(2)O and methanol-H(2)O(2). The as-prepared products were characterized by X-ray powder diffraction, N(2) surface area adsorption, scanning electron microscope, Fourier transform infrared spectroscopy, UV-vis absorption spectra and X-ray fluorescence. The influences of reaction conditions such as the ratio of methanol to H(2)O(2) or methanol to H(2)O, reaction temperature on the phase, crystallizability and purity of the (oxy)fluorides products were discussed in detail. Meanwhile, the photocatalytic behaviors of the as-prepared K(2)TiF(6), K(2)TiOF(4), K(3)TiOF(5) and K(7)Ti(4)O(4)F(7) were evaluated by degradation of rhodamine B molecules, and the results showed that all of the products possessed photocatalytic activities in the order of K(2)TiOF(4)>K(2)TiF(6)>K(7)Ti(4)O(4)F(7)>K(3)TiOF(5) at room temperature under the UV light.

  13. Y2K UPDATE

    CERN Multimedia

    Sverre JARP

    1999-01-01

    Concerning Y2K preparation, please note the following:Everybody, who has a NICE installation on his/her PC, needs to log in to NICE at least once before Xmas to get the Y2K update installed. This applies especially to dual boot systems.The test schedule on Y2Kplus.cern.ch will be prolonged. The last restart took place on 10 November and two more will take place on 24 November and 8 December, respectively. The Oracle users responsible for the maintenance of Oracle Forms applications which include PL/SQL blocks where date fields are handled with the default format are requested to contact oracle.support@cern.ch at their earliest convenience.Sverre Jarp (CERN Y2K co-ordinator, phone: 74944)

  14. The 4 K Stirling cryocooler demonstration

    Science.gov (United States)

    Stacy, W. Dodd

    1992-01-01

    This report briefly summarizes the results and conclusions from an SBIR program intended to demonstrate an innovative Stirling cycle cryocooler concept for efficiently lifting heat from 4 K. Refrigeration at 4 K, a temperature useful for superconductors and sensitive instruments, is beyond the reach of conventional regenerative thermodynamic cycles due to the rapid loss of regenerator matrix heat capacity at temperatures below about 20 K. To overcome this fundamental limit, the cryocooler developed under this program integrated three unique features: recuperative regeneration between the displacement gas flow streams of two independent Stirling cycles operating at a 180 degree phase angle, tailored distortion of the two expander volume waveforms from sinusoidal to perfectly match the instantaneous regenerator heat flux from the two cycles and thereby unload the regenerator, and metal diaphragm working volumes to promote near isothermal expansion and compression processes. Use of diaphragms also provides unlimited operating life potential and eliminates bearings and high precision running seals. A phase 1 proof-of-principle experiment demonstrated that counterflow regenerator operation between 77 K and 4 K increases regenerator effectiveness by minimizing metal temperature transient cycling. In phase 2, a detailed design package for a breadboard cryocooler was completed. Fabrication techniques were successfully developed for manufacturing high precision miniature parallel plate recuperators, and samples were produced and inspected. Process development for fabricating suitably flat diaphragms proved more difficult and expensive than anticipated, and construction of the cryocooler was suspended at a completion level of approximately 75%. Subsequent development efforts on other projects have successfully overcome diaphragm fabrication difficulties, and alternate funding is currently being sought for completion and demonstration testing of the 4 K Stirling cryocooler.

  15. Experimental results of a 3 k Wh thermochemical heat storage module for space heating application

    NARCIS (Netherlands)

    Finck, C.J.; Henquet, E.M.R.; Soest, C.F.L. van; Oversloot, H.P.; Jong, A.J. de; Cuypers, R.; Spijker, J.C. van 't

    2014-01-01

    A 3 kWh thermochemical heat storage (TCS) module was built as part of an all-in house system implementation focusing on space heating application at a temperature level of 40 ºC and a temperature lift of 20 K. It has been tested and measurements showed a maximum water circuit temperature span

  16. k-visit Attribute Grammars

    DEFF Research Database (Denmark)

    Nielson, Hanne Riis; Skyum, S.

    1981-01-01

    It is shown that any well-defined attribute grammar is k-visit for some k. Furthermore, it is shown that given a well-defined grammar G and an integer k, it is decidable whether G is k-visit. Finally it is shown that the k-visit grammars specify a proper hierarchy with respect to translations...

  17. Notched K-wire for low thermal damage bone drilling.

    Science.gov (United States)

    Liu, Yao; Belmont, Barry; Wang, Yiwen; Tai, Bruce; Holmes, James; Shih, Albert

    2017-07-01

    The Kirschner wire (K-wire) is a common bone drilling tool in orthopedic surgery to affix fractured bone. Significant heat is produced due to both the cutting and the friction between the K-wire and the bone debris during drilling. Such heat can result in high temperatures, leading to osteonecrosis and other secondary injuries. To reduce thermal injury and other high-temperature associated complications, a new K-wire design with three notches along the three-plane trocar tip fabricated using a thin micro-saw tool is studied. These notches evacuate bone debris and reduce the clogging and heat generation during bone drilling. A set of four K-wires, one without notches and three notched, with depths of 0.5, 0.75, and 1mm, are evaluated. Bone drilling experiments conducted on bovine cortical bone show that notched K-wires could effectively decrease the temperature, thrust force, and torque during bone drilling. K-wires with notches 1mm deep reduced the thrust force and torque by approximately 30%, reduced peak temperatures by 43%, and eliminated blackened burn marks in bone. This study demonstrates that a simple modification of the tip of K-wires can effectively reduce bone temperatures during drilling. Copyright © 2017 IPEM. Published by Elsevier Ltd. All rights reserved.

  18. Temperature-dependent piezoresistivity in an MWCNT/epoxy nanocomposite temperature sensor with ultrahigh performance

    Science.gov (United States)

    Alamusi; Li, Yuan; Hu, Ning; Wu, Liangke; Yuan, Weifeng; Peng, Xianghe; Gu, Bin; Chang, Christiana; Liu, Yaolu; Ning, Huiming; Li, Jinhua; Surina; Atobe, Satoshi; Fukunaga, Hisao

    2013-11-01

    A temperature sensor was fabricated from a polymer nanocomposite with multi-walled carbon nanotube (MWCNT) as nanofiller (i.e., MWCNT/epoxy). The electrical resistance and temperature coefficient of resistance (TCR) of the temperature sensor were characterized experimentally. The effects of temperature (within the range 333-373 K) and MWCNT content (within the range 1-5 wt%) were investigated thoroughly. It was found that the resistance increases with increasing temperature and decreasing MWCNT content. However, the resistance change ratio related to the TCR increases with increasing temperature and MWCNT content. The highest value of TCR (0.021 K-1), which was observed in the case of 5 wt% MWCNT, is much higher than those of traditional metals and MWCNT-based temperature sensors. Moreover, the corresponding numerical simulation—conducted to explain the above temperature-dependent piezoresistivity of the nanocomposite temperature sensor—indicated the key role of a temperature-dependent tunneling effect.

  19. Présentation d'une boucle prototype de pompe à chaleur à absorption haute température industrielle de 100 kW Description of a 100-Kw Prototype Loop for an Industrial High-Temperature Absorption Heat-Pump

    Directory of Open Access Journals (Sweden)

    Thomas D.

    2006-11-01

    Full Text Available II apparait indispensable, dans le contexte énergétique actuel, de mettre au point de nouvelles techniques de revalorisation d'énergie. Les pompes à chaleur à absorption peuvent, dans certains secteurs industriels, apporter des solutions particulièrement intéressantes par rapport aux pompes à chaleur à compression notamment, en particulier dans le domaine des hautes températures de revalorisation (120-150 °C. Pour mener à bien les études entreprises sur ce thème, le Gaz de France travaille en étroite collaboration avec l'Institut du Génie Chimique de Toulouse et la Société Creusot-Loire. Dans une première partie, les auteurs rappellent les principes de fonctionnement des pompes à chaleurs à absorption et leurs caractères spécifiques. Quelques exemples d'applications industrielles sont proposés. Ils présentent, dans une deuxième partie, la boucle prototype de 100 kW qui a été réalisée et décrivent ses caractéristiques, son cycle de fonctionnement et le programme des essais. Ce pilote de taille semi-industrielle utilise le couple eau-bromure de lithium. La définition d'un prototype industriel de pompe à chaleur à absorption haute température et les compléments de recherche entrepris dans ce domaine constituent la troisième partie de la communication. In the present energy context, it seems absolutely necessary to develop new techniques for energy upgrading. In some industrial sectors, absorption heat pumps may bring particularly interesting solutions compared, in particular, to compression heat pumps, especially in the field of high-temperature upgrading (120-150°C. Reasearch is being done in this field by Gaz de France in close collaboration with the Institut du Génie Chimique in Toulouse and with Creusot-Loire. ,The first part of this article reviews the operating principles of absorption heat pumps and their specific features. Some examples of industrial applications are then proposed. The second part

  20. S K Panda

    Indian Academy of Sciences (India)

    Home; Journals; Sadhana. S K Panda. Articles written in Sadhana. Volume 37 Issue 2 April 2012 pp 223-240. Multi-objective parametric optimization of powder mixed electro-discharge machining using response surface methodology and non-dominated sorting genetic algorithm · Soumyakant Padhee Niharranjan Nayak ...

  1. Khosla, Prof. Pradeep K

    Indian Academy of Sciences (India)

    Pradeep K. Address: Chancellor, University of California, 9500, Gilman Drive # 0005, La Jolla, CA 92093, USA Contact: Office: (+1-858) 534 3135. Residence: (+1-412) 708 4831. Fax: (+1-858) 534 6523. Email: pKhosla57@me.com, pkhosla@ucsd.edu. http://chancellor.ucsd.edu/ · YouTube · Twitter · Facebook · Blog ...

  2. K Neelakanteshwar Patil

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Biosciences. K Neelakanteshwar Patil. Articles written in Journal of Biosciences. Volume 40 Issue 1 March 2015 pp 13-30 Articles. Structural studies on Mycobacterium tuberculosis RecA: Molecular plasticity and interspecies variability · Anu V Chandran J Rajan Prabu Astha Nautiyal K ...

  3. K. R. Sunil Kumar

    Indian Academy of Sciences (India)

    K. R. Sunil Kumar. Articles written in Journal of Genetics. Volume 94 Issue 4 December 2015 pp 741-748 Research Article. Identification and introgression of QTLs implicated in resistance to sorghum downy mildew (Peronosclerospora sorghi (Weston and Uppal) C. G. Shaw) in maize through marker-assisted selection.

  4. sunil k sharma

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Chemical Sciences. SUNIL K SHARMA. Articles written in Journal of Chemical Sciences. Volume 129 Issue 2 February 2017 pp 211-222 Regular Article. Synthesis and antibacterial activity screening of quaternary ammonium derivatives of triazolyl pyranochromenones · PREETI YADAV BIPUL ...

  5. Eske K. Mathiesen

    DEFF Research Database (Denmark)

    Skiveren, Tobias; Gregersen, Martin

    Den fjerde bog i Arenas serie af monografier – Arena Monografi – om dansk samtidslitteratur handler om digteren Eske K. Mathiesen. Eske K. Mathiesen blev født i 1944 og debuterede i 1976 med digtsamlingen Fra spætternes have. I en stil, der aldrig er storladen, men altid er overraskende, retter...... Mathiesen sit skæve blik mod de allermindste og upåagtede fænomener, der imidlertid altid tilkendes en forunderlig vitalitet. Regnormen bliver forelsket. Skarnbassen får kosmiske dimensioner. Den oversete væverskes monotone arbejdslyde forvandles til stor poesi. I bogen Eske K. Mathiesen undersøger Martin....... For det andet Mathiesens grønne sensibilitet, som lader disse digte vise os naturens selvstændige liv og virkelyst. Og for det tredje det røde engagement, der ligger bag Mathiesens interesse for ellers marginaliserede eksistenser og måder at være til på. Eske K. Mathiesen har alt for længe levet en...

  6. Statskonsulent K. Hansen

    DEFF Research Database (Denmark)

    Kristensen, Birgit Juul

    2011-01-01

    Beskrivelse af gammel bogsamling fra Ladelund Landbrugsskole (nu Syddansk Universitetsbibliotek i Esbjerg), samlet af Statskonsulent K. Hansen (1858-1941). Derudover en fremstilling af hans liv og virke som statskonsulent i planteavl for Øerne, leder af Dansk Landbrugsmuseum, forfatter af...

  7. K. 0. Ipintnoroti

    African Journals Online (AJOL)

    1993-12-07

    K. 0. Ipintnoroti. Chemistry Department, Federal University of Technolo. Akure, Ondo State, Nigeria. he ur. _ _. (Received December 7, 1993). ABSTRACT. The suitability of tri-n-octyl pltosphine oxideftoluene as a solvent extraction system for Zn“ recovery fi'on1 acid chloride solutions was investigated.' The effects of the.

  8. Chakraborti, Dr Pradip K

    Indian Academy of Sciences (India)

    Elected: 2010 Section: General Biology. Chakraborti, Dr Pradip K Ph.D. (Visva Bharati), FNASc, FNA. Date of birth: 7 November 1956. Specialization: Biochemistry and Molecular Microbiology, Prokaryotic Signal Transduction. Address: Chief Scientist, Institute of Microbial Technology, Sector 39A, Chandigarh 160 036, U.T.

  9. Mishra, Dr Rakesh K

    Indian Academy of Sciences (India)

    Mishra, Dr Rakesh K Ph.D. (Allahabad), FNASc, FNA. Date of birth: 14 April 1961. Specialization: Genomics, Chromatin, Epigenetics Address: Director, Centre for Cellular & Molecular Biology, Uppal Road, Hyderabad 500 007, A.P.. Contact: Office: (040) 2719 2600. Residence: (040) 2720 6400. Mobile: 94419 02188

  10. K-6 Science Curriculum.

    Science.gov (United States)

    Blueford, J. R.; And Others

    A unified science approach is incorporated in this K-6 curriculum mode. The program is organized into six major cycles. These include: (1) science, math, and technology cycle; (2) universe cycle; (3) life cycle; (4) water cycle; (5) plate tectonics cycle; and (6) rock cycle. An overview is provided of each cycle's major concepts. The topic…

  11. Hall Sensors for Extreme Temperatures

    Directory of Open Access Journals (Sweden)

    Maciej Oszwaldowski

    2011-01-01

    Full Text Available We report on the preparation of the first complete extreme temperature Hall sensor. This means that the extreme-temperature magnetic sensitive semiconductor structure is built-in an extreme-temperature package especially designed for that purpose. The working temperature range of the sensor extends from −270 °C to +300 °C. The extreme-temperature Hall-sensor active element is a heavily n-doped InSb layer epitaxially grown on GaAs. The magnetic sensitivity of the sensor is ca. 100 mV/T and its temperature coefficient is less than 0.04 %/K. This sensor may find applications in the car, aircraft, spacecraft, military and oil and gas industries.

  12. Type II Superlattice as Low-Temperature Peltier Refrigerator (4K-150K)

    Science.gov (United States)

    2012-02-29

    directional symmetry of the Seebeck tensor needs to be broken. Thermomagnetic effects such as the Ettingshausen effect require an external magnetic field...exploit this anisotropic conductivity to weight the resulting total Seebeck tensor to opposite signs of Seebeck effect for orthogonal directions...to determine the conductivity and Seebeck tensor components: where mi represents the effective mass component of the band of interest n or p

  13. Measurements of CP-Violating Asymmetries in the Decay B0-->K+K-K0

    CERN Document Server

    Aubert, B; Boutigny, D; Karyotakis, Yu; Lees, J P; Poireau, V; Prudent, X; Tisserand, V; Zghiche, A; Garra Tico, J; Graugès-Pous, E; López, L; Palano, A; Eigen, G; Stugu, B; Sun, L; Abrams, G S; Battaglia, M; Brown, D N; Button-Shafer, J; Cahn, R N; Groysman, Y; Jacobsen, R G; Kadyk, J A; Kerth, L T; Kolomensky, Yu G; Kukartsev, G; Lopes-Pegna, D; Lynch, G; Mir, L M; Orimoto, T J; Ronan, M T; Tackmann, K; Wenzel, W A; Del Amo-Sánchez, P; Hawkes, C M; Watson, A T; Held, T; Koch, H; Lewandowski, B; Pelizaeus, M; Schröder, T; Steinke, M; Walker, D; Asgeirsson, D J; Çuhadar-Dönszelmann, T; Fulsom, B G; Hearty, C; Mattison, T S; McKenna, J A; Khan, A; Saleem, M; Teodorescu, L; Blinov, V E; Bukin, A D; Druzhinin, V P; Golubev, V B; Onuchin, A P; Serednyakov, S I; Skovpen, Yu I; Solodov, E P; Todyshev, K Yu; Bondioli, M; Curry, S; Eschrich, I; Kirkby, D; Lankford, A J; Lund, P; Mandelkern, M; Martin, E C; Stoker, D P; Abachi, S; Buchanan, C; Foulkes, S D; Gary, J W; Liu, F; Long, O; Shen, B C; Zhang, L; Paar, H P; Rahatlou, S; Sharma, V; Berryhill, J W; Campagnari, C; Cunha, A; Dahmes, B; Hong, T M; Kovalskyi, D; Richman, J D; Beck, T W; Eisner, A M; Flacco, C J; Heusch, C A; Kroseberg, J; Lockman, W S; Schalk, T; Schumm, B A; Seiden, A; Williams, D C; Wilson, M G; Winstrom, L O; Chen, E; Cheng, C H; Fang, F; Hitlin, D G; Narsky, I; Piatenko, T; Porter, F C; Andreassen, R; Mancinelli, G; Meadows, B T; Mishra, K; Sokoloff, M D; Blanc, F; Bloom, P C; Chen, S; Ford, W T; Hirschauer, J F; Kreisel, A; Nagel, M; Nauenberg, U; Olivas, A; Smith, J G; Ulmer, K A; Wagner, S R; Zhang, J; Gabareen, A M; Soffer, A; Toki, W H; Wilson, R J; Winklmeier, F; Zeng, Q; Altenburg, D D; Feltresi, E; Hauke, A; Jasper, H; Merkel, J; Petzold, A; Spaan, B; Wacker, K; Brandt, T; Klose, V; Kobel, M J; Lacker, H M; Mader, W F; Nogowski, R; Schubert, J; Schubert, K R; Schwierz, R; Sundermann, J E; Volk, A; Bernard, D; Bonneaud, G R; Latour, E; Lombardo, V; Thiebaux, C; Verderi, M; Clark, P J; Gradl, W; Muheim, F; Playfer, S; Robertson, A I; Xie, Y; Andreotti, M; Bettoni, D; Bozzi, C; Calabrese, R; Cecchi, A; Cibinetto, G; Franchini, P; Luppi, E; Negrini, M; Petrella, A; Piemontese, L; Prencipe, E; Santoro, V; Anulli, F; Baldini-Ferroli, R; Calcaterra, A; De Sangro, R; Finocchiaro, G; Pacetti, S; Patteri, P; Peruzzi, I M; Piccolo, M; Rama, M; Zallo, A; Buzzo, A; Contri, R; Lo Vetere, M; Macri, M M; Monge, M R; Passaggio, S; Patrignani, C; Robutti, E; Santroni, A; Tosi, S; Chaisanguanthum, K S; Morii, M; Wu, J; Dubitzky, R S; Marks, J; Schenk, S; Uwer, U; Bard, D J; Dauncey, P D; Flack, R L; Nash, J A; Nikolich, M B; Panduro-Vazquez, W; Tibbetts, M; Behera, P K; Chai, X; Charles, M J; Mallik, U; Meyer, N T; Ziegler, V; Cochran, J; Crawley, H B; Dong, L; Eyges, V; Meyer, W T; Prell, S; Rosenberg, E I; Rubin, A E; Gritsan, A V; Guo, Z J; Lae, C K; Denig, A G; Fritsch, M; Schott, G; Arnaud, N; Bequilleux, J; Davier, M; Grosdidier, G; Höcker, A; Lepeltier, V; Le Diberder, F R; Lutz, A M; Pruvot, S; Rodier, S; Roudeau, P; Schune, M H; Serrano, J; Sordini, V; Stocchi, A; Wang, W F; Wormser, G; Lange, D J; Wright, D M; Bingham, I; Chavez, C A; Forster, I J; Fry, J R; Gabathuler, E; Gamet, R; Hutchcroft, D E; Payne, D J; Schofield, K C; Touramanis, C; Bevan, A J; George, K A; Di Lodovico, F; Menges, W; Sacco, R; Cowan, G; Flächer, H U; Hopkins, D A; Paramesvaran, S; Salvatore, F; Wren, A C; Brown, D N; Davis, C L; Allison, J; Barlow, N R; Barlow, R J; Chia, Y M; Edgar, C L; Lafferty, G D; West, T J; Yi, J I; Anderson, J; Chen, C; Jawahery, A; Roberts, D A; Simi, G; Tuggle, J M; Blaylock, G; Dallapiccola, C; Hertzbach, S S; Li, X; Moore, T B; Salvati, E; Saremi, S; Cowan, R; Dujmic, D; Fisher, P H; Koeneke, K; Sciolla, G; Sekula, S J; Spitznagel, M; Taylor, F; Yamamoto, R K; Zhao, M; Zheng, Y; Mclachlin, S E; Patel, P M; Robertson, S H; Lazzaro, A; Palombo, F; Bauer, J M; Cremaldi, L; Eschenburg, V; Godang, R; Kroeger, R; Sanders, D A; Summers, D J; Zhao, H W; Brunet, S; Côté, D; Simard, M; Taras, P; Viaud, F B; Nicholson, H; De Nardo, Gallieno; Fabozzi, F; Lista, L; Monorchio, D; Sciacca, C; Baak, M A; Raven, G; Snoek, H L; Jessop, C P; LoSecco, J M; Benelli, G; Corwin, L A; Honscheid, K; Kagan, H; Kass, R; Morris, J P; Rahimi, A M; Regensburger, J J; Wong, Q K; Blount, N L; Brau, J E; Frey, R; Igonkina, O; Kolb, J A; Lu, M; Rahmat, R; Sinev, N B; Strom, D; Strube, J; Torrence, E; Gagliardi, N; Gaz, A; Margoni, M; Morandin, M; Pompili, A; Posocco, M; Rotondo, M; Simonetto, F; Stroili, R; Voci, C; Ben-Haim, E; Briand, H; Calderini, G; Chauveau, J; David, P; Del Buono, L; De La Vaissière, C; Hamon, O; Leruste, P; Malcles, J; Ocariz, J; Pérez, A; Gladney, L; Biasini, M; Covarelli, R; Manoni, E; Angelini, C; Batignani, G; Bettarini, S; Carpinelli, M; Cenci, R; Cervelli, A; Forti, F; Giorgi, M A; Lusiani, A; Marchiori, G; Mazur, M A; Morganti, M; Neri, N; Paoloni, E; Rizzo, G; Walsh, J J; Haire, M; Biesiada, J; Elmer, P; Lau, Y P; Lü, C; Olsen, J; Smith, A J S; Telnov, A V; Baracchini, E; Bellini, F; Cavoto, G; D'Orazio, A; Del Re, D; Di Marco, E; Faccini, R; Ferrarotto, F; Ferroni, F; Gaspero, M; Jackson, P D; Li Gioi, L; Mazzoni, M A; Morganti, S; Piredda, G; Polci, F; Renga, F; Voena, C; Ebert, M; Hartmann, T; Schröder, H; Waldi, R; Adye, T; Castelli, G; Franek, B; Olaiya, E O; Ricciardi, S; Röthel, W; Wilson, F F; Aleksan, R; Emery, S; Escalier, M; Gaidot, A; Ganzhur, S F; Hamel de Monchenault, G; Kozanecki, W; Vasseur, G; Yéche, C; Zito, M; Chen, X R; Liu, H; Park, W; Purohit, M V; Wilson, J R; Allen, M T; Aston, D; Bartoldus, R; Bechtle, P; Berger, N; Claus, R; Coleman, J P; Convery, M R; Dingfelder, J C; Dorfan, J; Dubois-Felsmann, G P; Dunwoodie, W; Field, R C; Glanzman, T; Gowdy, S J; Graham, M T; Grenier, P; Hast, C; Hrynóva, T; Innes, W R; Kaminski, J; Kelsey, M H; Kim, H; Kim, P; Kocian, M L; Leith, D W G S; Li, S; Luitz, S; Lüth, V; Lynch, H L; MacFarlane, D B; Marsiske, H; Messner, R; Müller, D R; O'Grady, C P; Ofte, I; Perazzo, A; Perl, M; Pulliam, T; Ratcliff, B N; Roodman, A; Salnikov, A A; Schindler, R H; Schwiening, J; Snyder, A; Stelzer, J; Su, D; Sullivan, M K; Suzuki, K; Swain, S K; Thompson, J M; Vavra, J; Van Bakel, N; Wagner, A P; Weaver, M; Wisniewski, W J; Wittgen, M; Wright, D H; Yarritu, A K; Yi, K; Young, C C; Burchat, P R; Edwards, A J; Majewski, S A; Petersen, B A; Wilden, L; Ahmed, S; Alam, M S; Bula, R; Ernst, J A; Jain, V; Pan, B; Saeed, M A; Wappler, F R; Zain, S B; Bugg, W; Krishnamurthy, M; Spanier, S M; Eckmann, R; Ritchie, J L; Ruland, A M; Schilling, C J; Schwitters, R F; Izen, J M; Lou, X C; Ye, S; Bianchi, F; Gallo, F; Gamba, D; Pelliccioni, M; Bomben, M; Bosisio, L; Cartaro, C; Cossutti, F; Della Ricca, G; Lanceri, L; Vitale, L; Azzolini, V; Lopez-March, N; Martínez-Vidal, F; Milanes, D A; Oyanguren, A; Albert, J; Banerjee, Sw; Bhuyan, B; Hamano, K; Kowalewski, R; Nugent, I M; Roney, J M; Sobie, R J; Back, J J; Harrison, P F; Ilic, J; Latham, T E; Mohanty, G B; Pappagallo, M; Band, H R; Chen, X; Dasu, S; Flood, K T; Hollar, J J; Kutter, P E; Pan, Y; Pierini, M; Prepost, R; Wu, S L; Neal, H

    2007-01-01

    We analyze the decay B0 --> K+ K- K0 using 383 million B-Bbar events collected by the BaBar detector at SLAC to extract CP violation parameter values over the Dalitz plot. Combining all K+ K- K0 events, we find A_CP = -0.015 +/- 0.077 +/- 0.053 and beta_eff = 0.352 +/- 0.076 +/- 0.026 rad, corresponding to a CP violation significance of 4.8 sigma. A second solution near pi/2 - beta_eff is disfavored with a significance of 4.5 sigma. We also report A_CP and beta_eff separately for decays to phi(1020) K0, f0(980) K0, and K+ K- K0 with m_{K+ K-} > 1.1 GeV/c^2.

  14. Semiconductor Sensors for a Wide Temperature Range

    OpenAIRE

    Nikolay GORBACHUK; Mikhail LARIONOV; Aleksey FIRSOV; Nikolay SHATIL

    2014-01-01

    Prototype sensors are described that are applicable for pressure, position, temperature, and field measurements in the temperature range of 4.2 to 300 K. The strain gauges utilize the silicon substrate and thin film technology. The tensosensitivity of strain sensors is 40 µV/mln-1 or better depending on metrological characteristics of semiconductor films, orientation, and current. The temperature sensors (thermistors) make use of the germanium powder bulk. The temperature coefficient of resis...

  15. Thermoluminescence in alkali halides irradiated at 80K; Termoluminiscencia en haluros alcalinos irradiados a 80K

    Energy Technology Data Exchange (ETDEWEB)

    Jimenez de Castro, M.

    1978-07-01

    The thermoluminescence, the thermally stimulated currents and the thermal stability of the F centres induced in pure NaCl and KC1 crystals by X irradiation at 80K have been studied in detail, In the range between 80 and 300K. The thermoluminescent processes induced by illumination at 80K with F light in samples previously irradiated at room temperature has also been studied. It has been clearly observed the existence of thermoluminescent processes due to electrons and holes thermally released from traps, in which the F centres are not involved. The existence of hole-F centre recombination has not been observed. There are several thermoluminescent processes in both materials which are scribed to the recombination of F centres with mobile interstitial halogen atoms thermally released from traps, which are likely monovalent impurities in this temperature interval. The light emitting stage in these processes is originated by the formation of self trapped excitons. (Author) 66 refs.

  16. A study on low sintering-temperature (1 - x)(0.98(Bi0.5(Na0.78K0.22)0.5TiO3) - 0.02CuO) - xCoFe2O4 particulate composites

    Science.gov (United States)

    Oanh, Le Thi Mai; Van Minh, Nguyen; Ahn, Chang Won; Ullah, Aman; Kim, Ill Won

    2017-07-01

    Low sintering-temperature lead-free particulate composites of (1 - x)(0.98(Bi0.5(Na0.78 K0.22)0.5TiO3 - 0.02CuO) - ( x)CoFe2O4( x = 0-0.15) were synthesized by a combination of sol-gel and solid-state sintering methods. Structural, morphological, ferroelectric, and ferromagnetic properties of the composites were systematically investigated using different techniques. XRD results and FE-SEM images indicated the formation of single phase for parent matrix and the development of two component phases in all composites without any impurities. With increasing CoFe2O4 (CFO) content, P-E loops displayed a gradual increase in the coercive field ( E c). The ferroelectric properties of BNKTC were significantly reduced with increasing CFO content, evidenced by a slight decrease in saturated polarization ( P s), and a sharp reduction in normalized strain ( S max/ E max) and piezoelectric constant ( d 33). Conversely, M-H loops showed a remarkable improvement in ferromagnetism with increasing CFO content, which is a good sign for searching multiferroic composites.

  17. High Curie temperature and enhanced magnetoelectric properties of the laminated Li0.058(Na0.535K0.48)0.942NbO3/Co0.6Zn0.4Fe1.7Mn0.3O4composites.

    Science.gov (United States)

    Yang, Haibo; Zhang, Jintao; Lin, Ying; Wang, Tong

    2017-03-24

    Laminated magnetoelectric composites of Li 0.058 (Na 0.535 K 0.48 ) 0.942 NbO 3 (LKNN)/Co 0.6 Zn 0.4 Fe 1.7 Mn 0.3 O 4 (CZFM) prepared by the conventional solid-state sintering method were investigated for their dielectric, magnetic, and magnetoelectric properties. The microstructure of the laminated composites indicates that the LKNN phase and CZFM phase can coexist in the composites. Compared with the particulate magnetoelectric composites, the laminated composites have better piezoelectric and magnetoelectric properties due to their higher resistances and lower leakage currents. The magnetoelectric behaviors lie on the relative mass ratio of LKNN phase and CZFM phase. The laminated composites possess a high Curie temperature (T C ) of 463 °C, and the largest ME coefficient of 285 mV/cm Oe, which is the highest value for the lead-free bulk ceramic magnetoelectric composites so far.

  18. Vaporization thermodynamics of K2S and K2SO3

    Science.gov (United States)

    Bennet, J. E.

    1982-01-01

    The vaporization reactions, vapor pressures, and thermodynamics of potassium sulfide and potassium sulfite were studied for purposes of providing fundamental data for the seed cycle in magnetohydrodynamic electric power generation. Rate of effusion studies, supported by tube furnace experiments, X-ray powder diffraction, mass spectrometry and appropriate chemical analyses and tests, revealed that potassium sulfite disproportionates at high temperatures to form potassium sulfide and potassium sulfate. Potassium sulfide was observed to vaporize incongruently, the initial vapors beng predominantly potassium atoms, with minor species being S2 and various K-S molecules. The ratio of K/S2 in the vapor is very large initially and decreases steadily with prolonged heating. Several materials were evaluated for purposes of containing K2S/K2SO3 at temperatures or = 800 C: Pt, Mo, W, quartz, machinable glass, BN, high density graphite, pyrolytic coated graphite, and alumina. Of these, only alumina was observed to be chemically inert to both K2S but reacted with K2SO3. The other materials were not suitable for either substance. Thermodynamic calculations based on measured vapor pressures and approximate free energy functions are described. Results from isothermal total mass loss experiments and from thermogravimetric experiments are also included.

  19. Superconductivity at 28 K in Rb sub x C sub 60

    Energy Technology Data Exchange (ETDEWEB)

    Rosseinsky, M.J.; Ramirez, A.P.; Glarum, S.H.; Murphy, D.W.; Haddon, R.C.; Hebard, A.F.; Palstra, T.T.M.; Kortan, A.R.; Zahurak, S.M.; Makhija, A.V. (AT T Bell Laboratories, Murray Hill, New Jersey 07974-2070 (US))

    1991-05-27

    Meissner-effect and microwave-absorption measurements on bulk samples show that Rb{sub {ital x}}C{sub 60} is superconducting with a maximum transition temperature of 28 K. This is a 10-K (60%) increase over the K-doped material. Only Ba{sub 0.6}K{sub 0.4}BiO{sub 3} and the cuprate superconductors have higher transition temperatures.

  20. Sensing temperature.

    Science.gov (United States)

    Sengupta, Piali; Garrity, Paul

    2013-04-22

    Temperature is an omnipresent physical variable reflecting the rotational, vibrational and translational motion of matter, what Richard Feynman called the "jiggling" of atoms. Temperature varies across space and time, and this variation has dramatic effects on the physiology of living cells. It changes the rate and nature of chemical reactions, and it alters the configuration of the atoms that make up nucleic acids, proteins, lipids and other biomolecules, significantly affecting their activity. While life may have started in a "warm little pond", as Charles Darwin mused, the organisms that surround us today have only made it this far by devising sophisticated systems for sensing and responding to variations in temperature, and by using these systems in ways that allow them to persist and thrive in the face of thermal fluctuation. Copyright © 2013 Elsevier Ltd. All rights reserved.

  1. K V Siva Kumar

    Indian Academy of Sciences (India)

    Home; Journals; Bulletin of Materials Science. K V Siva Kumar. Articles written in Bulletin of Materials Science. Volume 30 Issue 4 August 2007 pp 357-363 Composites. Dielectric, elastic, anelastic and conductivity behaviour of ferroelectromagnetic composites, Ni0.5Zn0.5Fe1.95O4– + Ba0.8Pb0.2TiO3 · N Ramamanohar ...

  2. K. M. Keryoul and P. A. Sermon2

    African Journals Online (AJOL)

    There is a wealth of experimental work on how TiO2 affects the properties of Pt for alkanes transformation under strong metal support interaction (SMSI) conditions [1-6]. In the studies of the effects of reduction temperature on the catalytic activities [1-16], it has been shown that the high temperature reduction at 773 K (HTR) ...

  3. T2K & beyond

    CERN Document Server

    Catanesi, M G

    2016-01-01

    This article presents the status of the art of the T2K experiment and the measurements prospects for the incoming years. After a brief description of the experiment, the most recent results will be illustrated. The observation of the electron neutrino appearance in a muon neutrino beam and the new high-precision measurements of the mixing angle theta13 by the reactor experiments have led to a re-evaluation of the expected sensitivity to the oscillation parameters, relative to what was given in the original T2K proposal. For this reason the new physics potential of T2K for 7.8 x 10**21 p.o.t. and for a data exposure 3 times larger than it's expected to be reachable with accelerator and beam line upgrades in 2026 before the start of operation of the next generation of long-baseline neutrino oscillation experiments will also be described in the text. In particular the last challenging scenario opens the door to the possibility to obtain, under some conditions, a 3 sigma measurement excluding sin(deltaCP= 0.

  4. Flexible Multiplexed Surface Temperature Sensor

    Science.gov (United States)

    Daryabeigi, Kamran; Dillon-Townes, L. A.; Johnson, Preston B.; Ash, Robert L.

    1995-01-01

    Unitary array of sensors measures temperatures at points distributed over designated area on surface. Useful in measuring surface temperatures of aerodynamic models and thermally controlled objects. Made of combination of integrated-circuit microchips and film circuitry. Temperature-sensing chips scanned at speeds approaching 10 kHz. Operating range minus 40 degrees C to 120 degrees C. Flexibility of array conforms to curved surfaces. Multiplexer eliminates numerous monitoring cables. Control of acquisition and recording of data effected by connecting array to microcomputers via suitable interface circuitry.

  5. J.K. Nsiah

    African Journals Online (AJOL)

    Administrator

    segmented angular shapes have been, exhaustively, treated in this paper. Keywords: thermal equipment, neck, segmented angular shapes, castables, and high temperature refractory. INTRODUCTION. It is not easy to get ready-made shapes that are needed for the construction of refractory areas of round necks of boilers, ...

  6. ATHENA X-IFU 300 K-50 mK cryochain demonstrator cryostat

    Science.gov (United States)

    Prouvé, T.; Duval, J. M.; Charles, I.; Yamasaki, N. Y.; Mitsuda, K.; Nakagawa, T.; Shinozaki, K.; Tokoku, C.; Yamamoto, R.; Minami, Y.; Le Du, M.; Andre, J.; Daniel, C.; Linder, M.

    2018-01-01

    In the framework of the ESA X-ray mission ATHENA, scheduled for launch in 2028, an ESA Core Technology Program (CTP) was started in 2016 to build a flight like cryostat demonstrator in parallel with the phase A studies of the ATHENA/X-IFU instrument [1,2]. As part of this CTP, called the Detector Cooling System (DCS), design, manufacturing and test of a cryostat including existing space coolers will be done. In addition to the validation of thermal performance, a Focal Plan Assembly (FPA) demonstrator using Transition Edge Sensors (TES) detector technology will be also integrated and its performance characterized versus the environment provided by the cryostat. This is a unique opportunity to validate many crucial issues of the cryogenic part of such a sensitive instrument. A dedicated activity within this CTP-DCS is the demonstration of the 300 K-50 mK cooling chain in a Ground System Equipment (GSE) cryostat. The studies are focused on the operation of the space coolers, which is made possible by the use of a ground cooler for cooling cryogenic shields and mechanical supports. Thanks to the modularity of the cryostat, several cooling chains could be tested. In the base line configuration described here, the low temperature stage is the CEA hybrid sorption/ADR 50 mK cooler with thermal interfaces at 4 K and 2 K. 4 K cooling is accomplished by a 4 K Joule-Thomson (JT) cryocooler and its Stirling precooler provided by JAXA. Regarding the 2 K stage, at first a 2 K JT from JAXA will be used. Alternatively, a 2 K JT cooler from RAL could replace the JAXA 2 K JT. In both cases new prototype(s) of a 2 K JT will be implemented, precooled by the EM 15 K pule tube cooler from Air Liquide. This test program is also the opportunity to validate the operation of the cryochain with respect to various requirements, such as time constant and temperature stabilities. This would bring us valuable inputs to integrate the cryochain in DCS cryostat or for the X-IFU phase A studies

  7. TEMPERATURE DEPENDENCE OF THE THERMAL ...

    African Journals Online (AJOL)

    Thermal conductivity values, in the temperature range 300 – 1200 K, have been measured in air and at atmospheric pressure for a Kenyan kaolinite refractory with 0% - 50% grog proportions. The experimental thermal conductivity values were then compared with those calculated using the Zumbrunnen et al [1] and the ...

  8. Stability projections for high temperature superconductors

    Energy Technology Data Exchange (ETDEWEB)

    Laquer, H.L.; Edeskuty, F.J.; Hassenzahl, W.V.; Wipf, S.L.

    1989-03-01

    The stability of the new high temperature superconducting oxides has been analyzed, using the methodology developed over the last 25 years for conventional Type II superconductors. The results are presented in graphical form for the temperature range from 4 to 100 K. For a 90 K superconductor the first flux jump field peaks above 7 T at 60 K, ( and for a 120 k superconductor it peaks above 12 T at 75 K). The maximum adiabatically stable thickness increases dramatically. The linear dimension of the minimum propagating zone increases by a factor of 3 to 5, and the quench propagation velocity drops by 4 orders of magnitude. The high temperature superconducting materials will, therefore, have much higher stability than conventional Type II superconductors; their high flux jump fields will make ultra-fine multifilamentary conductors unnecessary and improve the outlook for tape conductors; the energy to create a propagating zone is increased; however, methods of coil protection will have to be modified.

  9. Low temperature (

    NARCIS (Netherlands)

    Rath, J.K.; de Jong, M.; Schropp, R.E.I.

    2008-01-01

    Amorphous silicon films have been made by HWCVD at a very low substrate temperature of ≤ 100 °C (in a dynamic substrate heating mode) without artificial substrate cooling, through a substantial increase of the filament–substrate distance ( 80 mm) and using one straight tantalum filament. The

  10. Superconductivity above 30 K in alkali-metal-doped hydrocarbon.

    Science.gov (United States)

    Xue, Mianqi; Cao, Tingbing; Wang, Duming; Wu, Yue; Yang, Huaixin; Dong, Xiaoli; He, Junbao; Li, Fengwang; Chen, G F

    2012-01-01

    The recent discovery of superconductivity with a transition temperature (T(c)) at 18 K in K(x)picene has extended the possibility of high-T(c) superconductors in organic materials. Previous experience based on similar hydrocarbons, like alkali-metal doped phenanthrene, suggested that even higher transition temperatures might be achieved in alkali-metals or alkali-earth-metals doped such polycyclic-aromatic-hydrocarbons (PAHs), a large family of molecules composed of fused benzene rings. Here we report the discovery of high-T(c) superconductivity at 33 K in K-doped 1,2:8,9-dibenzopentacene (C(30)H(18)). To our best knowledge, it is higher than any T(c) reported previously for an organic superconductor under ambient pressure. This finding provides an indication that superconductivity at much higher temperature may be possible in such PAHs system and is worthy of further exploration.

  11. Muscle K+, Na+, and Cl- disturbances and Na+-K+ pump inactivation: implications for fatigue

    DEFF Research Database (Denmark)

    McKenna, Michael J; Bangsbo, Jens; Renaud, Jean-Marc

    2008-01-01

    Membrane excitability is a critical regulatory step in skeletal muscle contraction and is modulated by local ionic concentrations, conductances, ion transporter activities, temperature, and humoral factors. Intense fatiguing contractions induce cellular K(+) efflux and Na(+) and Cl(-) influx......, these ionic changes depolarize sarcolemmal and t-tubular membranes to depress tetanic force and are thus likely to contribute to fatigue. Interestingly, less severe local ionic changes can also augment subtetanic force, suggesting that they may potentiate muscle contractility early in exercise. Increased Na......(+)-K(+)-ATPase activity during exercise stabilizes Na(+) and K(+) concentration gradients and membrane excitability and thus protects against fatigue. However, during intense contraction some Na(+)-K(+) pumps are inactivated and together with further ionic disturbances, likely precipitate muscle fatigue....

  12. Nernst-Ettingshausen Measurements on Aluminum Below 1K.

    Science.gov (United States)

    Amjadi, Ahmad

    We have constructed a system for transport measurements below 1K in magnetic fields up to 30kG, and used it to measure the high magnetic field limit of to the Nernst -Ettingshausen coefficient for a pure polycrystalline Aluminum sample at 210mk, where we expect phonon-drag contributions to be negligible. Previous measurements on Al were limited to above 1.8K. Our data indicate that the electron-phonon mass enhancement continues to appear in the off-diagonal component of the thermoelectric tensor coefficient at temperatures well below 1K. To within our measuring uncertainty, the enhancement in out data between 10 kG and 20 kG is consistent with (1 + (lamda)(,0)), in agreement with the low-temperature, high-field NE coefficient measurements of Al from 1.8K to 5K by Thaler, Fletcher and Bass (ref.3). The data are less consistent with an alternative prediction of (1 + 2/3(lamda)(,o)). As shown in Figure (4.2), above 20 kG the measured values of the NE coefficient start to drop from the saturated value at lower fields (i.e. between 10 kG and 20 kG). This effect is most likely due to magnetic breakdown in Al above 20 kG. By taking closely spaced data points from 20 kG to 30 kG, we looked for evidence of the quantum oscillations which accompany such breakdown in the thermopower of single crystal samples (ref.8). However, no convincing evidence of such oscillations was found. We assume that their absence is due to the polycrystalline nature of our sample.

  13. Low-Temperature Magnetic Anomaly in Magnetite

    OpenAIRE

    Svindrych, Zdenek; Janu, Zdenek; Kozlowski, Andrzej; Honig, Jurgen M.

    2013-01-01

    We have studied experimentally the responses of high quality single crystals of stoichiometric synthetic magnetite to applied weak dc and ac magnetic fields in the range of 6 K to 60 K, far below the Verwey transition. The results can be compared to so called Magnetic After Effects (MAE) measurements, which are the most extensive magnetic measurements of magnetite at these temperatures. We present a novel point of view on the relaxation phenomena encountered at these temperatures - the Low Te...

  14. High temperature storage loop :

    Energy Technology Data Exchange (ETDEWEB)

    Gill, David Dennis; Kolb, William J.

    2013-07-01

    A three year plan for thermal energy storage (TES) research was created at Sandia National Laboratories in the spring of 2012. This plan included a strategic goal of providing test capability for Sandia and for the nation in which to evaluate high temperature storage (>650ÀC) technology. The plan was to scope, design, and build a flow loop that would be compatible with a multitude of high temperature heat transfer/storage fluids. The High Temperature Storage Loop (HTSL) would be reconfigurable so that it was useful for not only storage testing, but also for high temperature receiver testing and high efficiency power cycle testing as well. In that way, HTSL was part of a much larger strategy for Sandia to provide a research and testing platform that would be integral for the evaluation of individual technologies funded under the SunShot program. DOEs SunShot program seeks to reduce the price of solar technologies to 6/kWhr to be cost competitive with carbon-based fuels. The HTSL project sought to provide evaluation capability for these SunShot supported technologies. This report includes the scoping, design, and budgetary costing aspects of this effort

  15. The e+e- to to K+ K- \\pi+\\pi-, K+ K- \\pi0\\pi0 and K+ K- K+ K- Cross Sections Measured with Initial-State Radiation

    Energy Technology Data Exchange (ETDEWEB)

    Aubert, B.; Bona, M.; Boutigny, D.; Karyotakis, Y.; Lees, J.P.; Poireau, V.; Prudent, X.; Tisserand, V.; Zghiche, A.; /Paris U., VI-VII; Garra Tico, J.; Grauges, E.; /Barcelona U., ECM; Lopez, L.; Palano, A.; /Bari U.; Eigen, G.; Stugu, B.; Sun, L.; /Bergen U.; Abrams, G.S.; Battaglia, M.; Brown, D.N.; Button-Shafer, J.; Cahn, R.N.; /Energy Sci.

    2007-05-04

    We study the processes e{sup +}e{sup -} {yields} K{sup +}K{sup -}{pi}{sup +}{pi}{sup -}{gamma}, K{sup +}K{sup -}{pi}{sup 0}{pi}{sup 0}{gamma} and K{sup +}K{sup -}K{sup +}K{sup -}{gamma}, where the photon is radiated from the initial state. About 34600, 4400 and 2300 fully reconstructed events respectively, are selected from 232 fb{sup -1} of BABAR data. The invariant mass of the hadronic final state defines the effective e{sup +}e{sup -} center-of-mass energy, so that the K{sup +}K{sup -}{pi}{sup +}{pi}{sup -}{gamma} data can be compared with direct measurements of the e{sup +}e{sup -} {yields} K{sup +}K{sup -}{pi}{sup +}{pi}{sup -}{gamma} reaction; no direct measurements exist for the e{sub +}e{sub -} {yields} K{sup +}K{sup -}{pi}{sup 0}{pi}{sup 0}{gamma} or e{sub +}e{sub -} {yields} K{sup +}K{sup -}K{sup +}K{sup -} reactions. Studying the structure of these events, we find contributions from a number of intermediate states, and we extract their cross sections where possible. In particular, we isolate the contribution from e{sup +}e{sup -} {yields} {phi}(1020)f{sub 0}(980) and study its structure near threshold. In the charmonium region, we observe the J/{psi} in all three final states and several intermediate states, as well as the {psi}/(2S) in some modes, and measure the corresponding branching fractions. We see no signal for the Y(4260) and obtain an upper limit of {Beta}{sub Y(4260){yields}{phi}{pi}{sup +}{pi}{sup -}} {center_dot} {Lambda}{sub ee}{sup Y} < 0.4 eV at 90% C.L.

  16. Thermal design improvements for 30kWe arcjet engines

    Science.gov (United States)

    Deininger, W. D.; Chopra, A.; King, D. Q.; Pivirotto, T. J.

    1988-01-01

    This paper describes two thermal design improvements for 30 kWe arcjet engines. A ZrB2 high temperature coating was used to increase the surface emissivity of the nozzle radiating surface, enabling lower temperature operation, which should lead to longer nozzle life. The ZrB2-coated engine operated about 120 C cooler than the uncoated baseline engine indicating a 30 percent increase in the surface emissivity. Additionally, a new engine design which has fewer active seals than previous designs and operates at lower overall component temperatures is described in detail. The nozzle on the new engine operated at a temperature of 1950 C at 30 kWe while the baseline engine nozzle reached 2000 C at 23 kWe. In addition, the back of the new engine was more than a factor of two cooler when compared to the baseline engine.

  17. Energy storage via high temperature superconductivity (SMES)

    Energy Technology Data Exchange (ETDEWEB)

    Mikkonen, R. [Tampere Univ. of Technology (Finland)

    1998-10-01

    The technology concerning high temperature superconductors (HTS) is matured to enabling different kind of prototype applications including SMES. Nowadays when speaking about HTS systems, attention is focused on the operating temperature of 20-30 K, where the critical current and flux density are fairly close to 4.2 K values. In addition by defining the ratio of the energy content of a novel HTS magnetic system and the required power to keep the system at the desired temperature, the optimum settles to the above mentioned temperature range. In the frame of these viewpoints a 5 kJ HTS SMES system has been designed and tested at Tampere University of Technology with a coil manufactured by American Superconductor (AMSC). The HTS magnet has inside and outside diameters of 252 mm and 317 mm, respectively and axial length of 66 mm. It operates at 160 A and carries a total of 160 kA-turns to store the required amount of energy. The effective magnetic inductance is 0.4 H and the peak axial field is 1.7 T. The magnet is cooled to the operating temperature of 20 K with a two stage Gifford-McMahon type cryocooler with a cooling power of 60 W at 77 K and 8 W at 20 K. The magnetic system has been demonstrated to compensate a short term loss of power of a sensitive consumer

  18. k-Inflation

    Science.gov (United States)

    Armendáriz-Picón, C.; Damour, T.; Mukhanov, V.

    1999-07-01

    It is shown that a large class of higher-order (i.e. non-quadratic) scalar kinetic terms can, without the help of potential terms, drive an inflationary evolution starting from rather generic initial conditions. In many models, this kinetically driven inflation (or ``k-inflation'' for short) rolls slowly from a high-curvature initial phase, down to a low-curvature phase and can exit inflation to end up being radiation-dominated, in a naturally graceful manner. We hope that this novel inflation mechanism might be useful in suggesting new ways of reconciling the string dilaton with inflation.

  19. Semiconductor Sensors for a Wide Temperature Range

    Directory of Open Access Journals (Sweden)

    Nikolay GORBACHUK

    2014-01-01

    Full Text Available Prototype sensors are described that are applicable for pressure, position, temperature, and field measurements in the temperature range of 4.2 to 300 K. The strain gauges utilize the silicon substrate and thin film technology. The tensosensitivity of strain sensors is 40 µV/mln-1 or better depending on metrological characteristics of semiconductor films, orientation, and current. The temperature sensors (thermistors make use of the germanium powder bulk. The temperature coefficient of resistance is within 50-100 % /K at 4.2 K. The magnetic field sensors use GaAs films that offer weak temperature dependence of parameters at high sensitivity (up to 300-400 mV/T.

  20. Observation of $\\pi^- K^+$ and $\\pi^+ K^-$ atoms

    CERN Document Server

    Adeva, B; The PS212 collaboration; Allkofer, Y.; Amsler, C.; Anania, A.; Aogaki, S.; Benelli, A.; Brekhovskikh, V.; Cechak, T.; Chiba, M.; Chliapnikov, P.; Doskarova, P.; Drijard, D.; Dudarev, A.; Dumitriu, D.; Fluerasu, D.; Gorin, A.; Gorchakov, O.; Gritsay, K.; Guaraldo, C.; Gugiu, M.; Hansroul, M.; Hons, Z.; Horikawa, S.; Iwashita, Y.; Karpukhin, V.; Kluson, J.; Kobayashi, M.; Kruglov, V.; Kruglova, L.; Kulikov, A.; Kulish, E.; Kuptsov, A.; Lamberto, A.; Lanaro, A.; Lednicky, R.; Marinas, C.; Martincik, J.; Nikitin, M.; Okada, K.; Olchevskii, V.; Pentia, M.; Penzo, A.; Plo, M.; Prusa, P.; Rappazzo, G.; Vidal, A.Romero; Ryazantsev, A.; Rykalin, V.; Saborido, J.; Sidorov, A.; Smolik, J.; Takeutchi, F.; Tauscher, L.; Trojek, T.; Trusov, S.; Urban, T.; Vrba, T.; Yazkov, V.; Yoshimura, Y.; Zhabitsky, M.; Zrelov, P.

    2016-01-01

    The observation of hydrogen-like $\\pi K$ atoms, consisting of $\\pi^- K^+$ or $\\pi^+ K^-$ mesons, is presented. The atoms have been produced by 24 GeV/$c$ protons from the CERN PS accelerator, interacting with platinum or nickel foil targets. The breakup (ionisation) of $\\pi K$ atoms in the same targets yields characteristic $\\pi K$ pairs, called ``atomic pairs'', with small relative momenta in the pair centre-of-mass system. The upgraded DIRAC experiment has observed $349\\pm62$ such atomic $\\pi K$ pairs, corresponding to a signal of 5.6 standard deviations.

  1. mK-Scanning Probe Microscope(mK-SPM) operating in a Cryogen-Free Dilution Refrigerator at 20mK

    Science.gov (United States)

    Dede, Munir; Karci, Ozgur; Snelling, Chris; Oral, Ahmet

    2012-02-01

    Dramatic increase in liquid helium price limits the usage of cryogenic equipment. Dry cryogen-free dilution refrigerators(DR) systems are promising platforms to run mK-Scanning Probe Microscopes(mK-SPM) systems with a number of operating modes: STM, AFM, MFM, EFM, SSRM, PFM, etc. We present the design of a mK-Scanning Probe Microscope (mK-SPM) operating in a cryogen-free DR. An Oxford Instrument cryogen-free DR(Triton DR200) with 200uW cooling power and 7mK base temperature is used for the experiments. A 1W Pulse Tube cryocooler is integrated into the DR. After wiring and attaching the microscope we achieved 20mK base temperature. Piezo driven Stick slip coarse approach mechanism is used to bring the sample in to close proximity of the sample. In these initial results we deliberately did not take any precautions to isolate the pumping lines, attached to the DR and the DR itself. The turbomolecular pump was attached directly to the top plate of the DR. We first tested our mK-SPM in Scanning Tunnelling Microscope (STM) mode as it is the most sensitive of the SPM techniques. An image, using a gold coated 6μm period calibration grating at 20mK, obtained under these rudimentary conditions.

  2. Low-temperature strain gauges based on silicon whiskers

    Directory of Open Access Journals (Sweden)

    Druzhinin A. A.

    2008-08-01

    Full Text Available To create low-temperature strain gauges based on p-type silicon whiskers tensoresistive characteristics of these crystals in 4,2—300 K temperature range were studied. On the basis of p-type Si whiskers with different resistivity the strain gauges for different materials operating at cryogenic temperatures with extremely high gauge factor at 4,2 K were developed, as well as strain gauges operating at liquid helium temperatures in high magnetic fields.

  3. Litteratursøk

    Directory of Open Access Journals (Sweden)

    Ingvild Kirkehei

    2013-11-01

    Full Text Available I denne artikkelen beskriver vi prinsipper for å utføre systematiske søk etter forskningslitteratur. I et godt søk bør det tas utgangspunkt i et klart formulert spørsmål som uttrykker hva slags forskning en ønsker å finne. For effektspørsmål kan dette formuleres ved hjelp av et PICO-skjema hvor det konkretiseres hvilke pasienter, tiltak og utfallsmål en er interessert i. I litteratursøket er det vanlig å bruke engelske søkeord som beskriver disse PICO-kategoriene. For å finne så mye relevant forskning som mulig, er det viktig å søke på alle relevante synonymer og staveformer. En kan også søke på standardiserte emneord som beskriver innholdet i publikasjonene. De boolske operatorene AND og OR brukes for å kombinere søkeordene i en samlet søkestrategi. For å få et håndterlig antall søketreff, kan søket avgrenses til publikasjonsår, spesielle aldersgrupper eller relevant studiedesign. Det kan være nyttig å dokumentere hvilke kilder og søkeord som er brukt. I de fleste kilder kan søket lagres og hentes frem senere og søkeresultatene kan eksporteres til referansehåndteringsprogrammer som Reference Manager eller EndNote. I noen tilfeller kan det være nyttig å supplere det systematiske søket med andre gjenfinningsmetoder som søk i studieregistre, gjennomgang av referanselister i relevante publikasjoner, siteringssøk og tips fra fageksperter. Litteratursøk er en ferdighet som læres ved praktisk øvelse og vi anbefaler alle å ta kontakt med en bibliotekar for å lære mer om dette.Kirkehei I, Ormstad SS. Searching for literature. Nor J Epidemiol 2013; 23 (2: 141-145.ENGLISH SUMMARY In this article we describe the basic principles on how to perform systematic searches for research literature. A well-conducted literature search is based on a clearly formulated question, expressing what one is looking for. Questions regarding effects of interventions can be structured with the aid of PICO, stating the population

  4. Signs of superconductivity at 110 K on inclusions of TiB sub k boride phases into titanium matrix

    CERN Document Server

    Volkov, V V; Berzverkhij, P P; Martynets, V G; Matizen, E V

    2002-01-01

    Verification of theoretical forecasts on the possibility of the high-temperature superconductivity of the high-temperature superconductivity (HTSC) in the TiB sub k titanium borides is accomplished. It is established that the jump-like change in the temperature dependence of the electric resistance R(T) at 110 K takes place on the titanium samples, the surfaces whereof are coated with the borides diffusion layers of the TiB sub k variable in-depth composition. This proves the presence of the borides diffusion layers are applied onto the metallic titanium by means of treating its surface with the B sub 2 H sub 6 + H sub 2 gases mixture at the temperature of 610-700 deg C with the subsequent annealing in vacuum. The boride layers composition is studied through the mass-spectrometry method

  5. K-East and K-West Reactors

    Data.gov (United States)

    Federal Laboratory Consortium — Hanford's "sister reactors", the K-East and the K-West Reactors, were built side-by-side in the early 1950's. The two reactors went operational within four months of...

  6. Measuring Systems for Thermometer Calibration in Low-Temperature Range

    Science.gov (United States)

    Szmyrka-Grzebyk, A.; Lipiński, L.; Manuszkiewicz, H.; Kowal, A.; Grykałowska, A.; Jancewicz, D.

    2011-12-01

    The national temperature standard for the low-temperature range between 13.8033 K and 273.16 K has been established in Poland at the Institute of Low Temperature and Structure Research (INTiBS). The standard consists of sealed cells for realization of six fixed points of the International Temperature Scale of 1990 (ITS-90) in the low-temperature range, an adiabatic cryostat and Isotech water and mercury triple-point baths, capsule standard resistance thermometers (CSPRT), and AC and DC bridges with standard resistors for thermometers resistance measurements. INTiBS calibrates CSPRTs at the low-temperature fixed points with uncertainties less than 1 mK. In lower temperature range—between 2.5 K and about 25 K — rhodium-iron (RhFe) resistance thermometers are calibrated by comparison with a standard which participated in the EURAMET.T-K1.1 comparison. INTiBS offers a calibration service for industrial platinum resistance thermometers and for digital thermometers between 77 K and 273 K. These types of thermometers may be calibrated at INTiBS also in a higher temperature range up to 550°C. The Laboratory of Temperature Standard at INTiBS acquired an accreditation from the Polish Centre for Accreditation. A management system according to EN ISO/IEC 17025:2005 was established at the Laboratory and presented on EURAMET QSM Forum.

  7. Potentiometric determination of K + ions using a K + -selective ...

    African Journals Online (AJOL)

    This paper describes analytical applications of K+-selective liquid membrane electrode. The membrane is the solution of the active complex formed by the K+ ions with dibenzo-18-crown-6 ionophore (DB-[18]-C-6) extracted in propylenecarbonate (PC). Successful application of the developed electrode for K+ ions ...

  8. ELEVATED TEMPERATURE EFFECTS ON THE ELECTRICAL ...

    African Journals Online (AJOL)

    The effects of elevated temperatures on the electrical properties of Bi metal probe to Si thin films had been investigated for electric field values 10-100V/m. Measurements of current (I) – voltage (V) characteristics were obtained at temperatures 300,320,340,360,380 and 400K respectively. The results indicated linear I–V ...

  9. Microchannel plate resistance at cryogenic temperatures

    CERN Document Server

    Roth, P

    2000-01-01

    The resistance R of a 'low-resistance' microchannel plate (MCP) electron multiplier was measured over the extended temperature range 4-293 K. The ratio R(T)/R(293 K) reached values of 10 sup 2 , 10 sup 3 and 10 sup 6 at temperatures T=59, 40 and 19 K, respectively. These results are interpreted in terms of variable range hopping conduction mechanisms in the reduced lead silicate MCP glass. The results may be important for cryogenic charged particle detection using MCPs, as, for example, in a recent proposal for a quantum computer.

  10. Observation of B0 -> K*0 K*0bar and search for B0 -> K*0 K*0

    CERN Document Server

    Aubert, B; Boutigny, D; Karyotakis, Yu; Lees, J P; Poireau, V; Prudent, X; Tisserand, V; Zghiche, A; Garra Tico, J; Graugès-Pous, E; López, L; Palano, A; Pappagallo, M; Eigen, G; Stugu, B; Sun, L; Abrams, G S; Battaglia, M; Brown, D N; Button-Shafer, J; Cahn, R N; Groysman, Y; Jacobsen, R G; Kadyk, J A; Kerth, L T; Kolomensky, Yu G; Kukartsev, G; Lopes-Pegna, D; Lynch, G; Mir, L M; Orimoto, T J; Osipenkov, I L; Ronan, M T; Tackmann, K; Tanabé, T; Wenzel, W A; Del Amo-Sánchez, P; Hawkes, C M; Watson, A T; Koch, H; Schröder, T; Walker, D; Asgeirsson, D J; Çuhadar-Dönszelmann, T; Fulsom, B G; Hearty, C; Mattison, T S; McKenna, J A; Khan, A; Saleem, M; Teodorescu, L; Blinov, V E; Bukin, A D; Druzhinin, V P; Golubev, V B; Onuchin, A P; Serednyakov, S I; Skovpen, Yu I; Solodov, E P; Todyshev, K Yu; Bondioli, M; Curry, S; Eschrich, I; Kirkby, D; Lankford, A J; Lund, P; Mandelkern, M; Martin, E C; Stoker, D P; Abachi, S; Buchanan, C; Foulkes, S D; Gary, J W; Liu, F; Long, O; Shen, B C; Vitug, G M; Zhang, L; Paar, H P; Rahatlou, S; Sharma, V; Berryhill, J W; Campagnari, C; Cunha, A; Dahmes, B; Hong, T M; Kovalskyi, D; Richman, J D; Beck, T W; Eisner, A M; Flacco, C J; Heusch, C A; Kroseberg, J; Lockman, W S; Schalk, T; Schumm, B A; Seiden, A; Wilson, M G; Winstrom, L O; Chen, E; Cheng, C H; Fang, F; Hitlin, D G; Narsky, I; Piatenko, T; Porter, F C; Andreassen, R; Mancinelli, G; Meadows, B T; Mishra, K; Sokoloff, M D; Blanc, F; Bloom, P C; Chen, S; Ford, W T; Hirschauer, J F; Kreisel, A; Nagel, M; Nauenberg, U; Olivas, A; Smith, J G; Ulmer, K A; Wagner, S R; Zhang, J; Gabareen, A M; Soffer, A; Toki, W H; Wilson, R J; Winklmeier, F; Altenburg, D D; Feltresi, E; Hauke, A; Jasper, H; Merkel, J; Petzold, A; Spaan, B; Wacker, K; Klose, V; Kobel, M J; Lacker, H M; Mader, W F; Nogowski, R; Schubert, J; Schubert, K R; Schwierz, R; Sundermann, J E; Volk, A; Bernard, D; Bonneaud, G R; Latour, E; Lombardo, V; Thiebaux, C; Verderi, M; Clark, P J; Gradl, W; Muheim, F; Playfer, S; Robertson, A I; Watson, J E; Xie, Y; Andreotti, M; Bettoni, D; Bozzi, C; Calabrese, R; Cecchi, A; Cibinetto, G; Franchini, P; Luppi, E; Negrini, M; Petrella, A; Piemontese, L; Prencipe, E; Santoro, V; Anulli, F; Baldini-Ferroli, R; Calcaterra, A; De Sangro, R; Finocchiaro, G; Pacetti, S; Patteri, P; Peruzzi, I M; Piccolo, M; Rama, M; Zallo, A; Buzzo, A; Contri, R; Lo Vetere, M; Macri, M M; Monge, M R; Passaggio, S; Patrignani, C; Robutti, E; Santroni, A; Tosi, S; Chaisanguanthum, K S; Morii, M; Wu, J; Dubitzky, R S; Marks, J; Schenk, S; Uwer, U; Bard, D J; Dauncey, P D; Flack, R L; Nash, J A; Panduro-Vazquez, W; Tibbetts, M; Behera, P K; Chai, X; Charles, M J; Mallik, U; Cochran, J; Crawley, H B; Dong, L; Eyges, V; Meyer, W T; Prell, S; Rosenberg, E I; Rubin, A E; Gao, Y Y; Gritsan, A V; Guo, Z J; Lae, C K; Denig, A G; Fritsch, M; Schott, G; Arnaud, N; Bequilleux, J; D'Orazio, A; Davier, M; Grosdidier, G; Höcker, A; Lepeltier, V; Le Diberder, F; Lutz, A M; Pruvot, S; Rodier, S; Roudeau, P; Schune, M H; Serrano, J; Sordini, V; Stocchi, A; Wang, W F; Wormser, G; Lange, D J; Wright, D M; Bingham, I; Burke, J P; Chavez, C A; Fry, J R; Gabathuler, E; Gamet, R; Hutchcroft, D E; Payne, D J; Schofield, K C; Touramanis, C; Bevan, A J; George, K A; Di Lodovico, F; Sacco, R; Cowan, G; Flächer, H U; Hopkins, D A; Paramesvaran, S; Salvatore, F; Wren, A C; Brown, D N; Davis, C L; Allison, J; Bailey, D; Barlow, N R; Barlow, R J; Chia, Y M; Edgar, C L; Lafferty, G D; West, T J; Yi, J I; Anderson, J; Chen, C; Jawahery, A; Roberts, D A; Simi, G; Tuggle, J M; Blaylock, G; Dallapiccola, C; Hertzbach, S S; Li, X; Moore, T B; Salvati, E; Saremi, S; Cowan, R; Dujmic, D; Fisher, P H; Koeneke, K; Sciolla, G; Spitznagel, M; Taylor, F; Yamamoto, R K; Zhao, M; Zheng, Y; Mclachlin, S E; Patel, P M; Robertson, S H; Lazzaro, A; Palombo, F; Bauer, J M; Cremaldi, L; Eschenburg, V; Godang, R; Kroeger, R; Sanders, D A; Summers, D J; Zhao, H W; Brunet, S; Côté, D; Simard, M; Taras, P; Viaud, F B; Nicholson, H; De Nardo, Gallieno; Fabozzi, F; Lista, L; Monorchio, D; Sciacca, C; Baak, M A; Raven, G; Snoek, H L; Jessop, C P; Knoepfel, K J; LoSecco, J M; Benelli, G; Corwin, L A; Honscheid, K; Kagan, H; Kass, R; Morris, J P; Rahimi, A M; Regensburger, J J; Sekula, S J; Wong, Q K; Blount, N L; Brau, J E; Frey, R; Igonkina, O; Kolb, J A; Lu, M; Rahmat, R; Sinev, N B; Strom, D; Strube, J; Torrence, E; Gagliardi, N; Gaz, A; Margoni, M; Morandin, M; Pompili, A; Posocco, M; Rotondo, M; Simonetto, F; Stroili, R; Voci, C; Ben-Haim, E; Briand, H; Calderini, G; Chauveau, J; David, P; Del Buono, L; De La Vaissière, C; Hamon, O; Leruste, P; Malcles, J; Ocariz, J; Pérez, A; Prendki, J; Gladney, L; Biasini, M; Covarelli, R; Manoni, E; Angelini, C; Batignani, G; Bettarini, S; Carpinelli, M; Cenci, R; Cervelli, A; Forti, F; Giorgi, M A; Lusiani, A; Marchiori, G; Mazur, M A; Morganti, M; Neri, N; Paoloni, E; Rizzo, G; Walsh, J J; Biesiada, J; Elmer, P; Lau, Y P; Lü, C; Olsen, J; Smith, A J S; Telnov, A V; Baracchini, E; Bellini, F; Cavoto, G; Del Re, D; Di Marco, E; Faccini, R; Ferrarotto, F; Ferroni, F; Gaspero, M; Jackson, P D; Li Gioi, L; Mazzoni, M A; Morganti, S; Piredda, G; Polci, F; Renga, F; Voena, C; Ebert, M; Hartmann, T; Schröder, H; Waldi, R; Adye, T; Castelli, G; Franek, B; Olaiya, E O; Röthel, W; Wilson, F F; Emery, S; Escalier, M; Gaidot, A; Ganzhur, S F; Hamel de Monchenault, G; Kozanecki, W; Vasseur, G; Yéche, C; Zito, M; Chen, X R; Liu, H; Park, W; Purohit, M V; White, R M; Wilson, J R; Allen, M T; Aston, D; Bartoldus, R; Bechtle, P; Claus, R; Coleman, J P; Convery, M R; Dingfelder, J C; Dorfan, J; Dubois-Felsmann, G P; Dunwoodie, W; Field, R C; Glanzman, T; Gowdy, S J; Graham, M T; Grenier, P; Hast, C; Innes, W R; Kaminski, J; Kelsey, M H; Kim, H; Kim, P; Kocian, M L; Leith, D W G S; Li, S; Luitz, S; Lüth, V; Lynch, H L; MacFarlane, D B; Marsiske, H; Messner, R; Müller, D R; O'Grady, C P; Ofte, I; Perazzo, A; Perl, M; Pulliam, T; Ratcliff, B N; Roodman, A; Salnikov, A A; Schindler, R H; Schwiening, J; Snyder, A; Su, D; Sullivan, M K; Suzuki, K; Swain, S K; Thompson, J M; Vavra, J; Wagner, A P; Weaver, M; Wisniewski, W J; Wittgen, M; Wright, D H; Yarritu, A K; Yi, K; Young, C C; Ziegler, V; Burchat, P R; Edwards, A J; Majewski, S A; Miyashita, T S; Petersen, B A; Wilden, L; Ahmed, S; Alam, M S; Bula, R; Ernst, J A; Jain, V; Pan, B; Saeed, M A; Wappler, F R; Zain, S B; Krishnamurthy, M; Spanier, S M; Eckmann, R; Ritchie, J L; Ruland, A M; Schilling, C J; Schwitters, R F; Izen, J M; Lou, X C; Ye, S; Bianchi, F; Gallo, F; Gamba, D; Pelliccioni, M; Bomben, M; Bosisio, L; Cartaro, C; Cossutti, F; Della Ricca, G; Lanceri, L; Vitale, L; Azzolini, V; Lopez-March, N; Martínez-Vidal, F; Milanes, D A; Oyanguren, A; Albert, J; Banerjee, Sw; Bhuyan, B; Hamano, K; Kowalewski, R; Nugent, I M; Roney, J M; Sobie, R J; Harrison, P F; Ilic, J; Latham, T E; Mohanty, G B; Band, H R; Chen, X; Dasu, S; Flood, K T; Hollar, J J; Kutter, P E; Pan, Y; Pierini, M; Prepost, R; Wu, S L; Neal, H

    2007-01-01

    We report the observation of the b -> d penguin-dominated decay B0 -> K*0 K*0bar with a sample of 383.2 +/- 4.2 million BBbar pairs collected with the BaBar detector at the PEP-II asymmetric-energy e^+e^- collider at the Stanford Linear Accelerator Center. The measured branching fraction is Br(B0 -> K*0 K*0bar) = [0.49^{+0.16}_{-0.13} +/- 0.05] x 10^{-6} and the fraction of longitudinal polarization f_L (B0 -> K*0 K*0bar) = 0.81^{+0.10}_{-0.12} +/- 0.06. The first error quoted is statistical and the second systematic. We also obtain an upper limit at the 90% confidence level on the branching fraction for Br(B0 ->K*0 K*0) < 0.18 x 10^{-6}.

  11. Validation of Temperature Measurements from the Airborne Raman Ozone Temperature and Aerosol Lidar During SOLVE

    Science.gov (United States)

    Burris, John; McGee, Thomas; Hoegy, Walter; Lait, Leslie; Twigg, Laurence; Sumnicht, Grant; Heaps, William; Hostetler, Chris; Bui, T. Paul; Neuber, Roland; hide

    2001-01-01

    The Airborne Raman Ozone, Temperature and Aerosol Lidar (AROTEL) participated in the recent Sage III Ozone Loss and Validation Experiment (SOLVE) by providing profiles of aerosols, polar stratospheric clouds (PSCs), ozone and temperature with high vertical and horizontal resolution. Temperatures were derived from just above the aircraft to approximately 60 kilometers geometric altitude with a reported vertical resolution of between 0.5 and 1.5 km. The horizontal footprint varied from 4 to 70 km. This paper explores the measurement uncertainties associated with the temperature retrievals and makes comparisons with independent, coincident, measurements of temperature. Measurement uncertainties range from 0.1 K to approximately 4 K depending on altitude and integration time. Comparisons between AROTEL and balloon sonde temperatures retrieved under clear sky conditions using both Rayleigh and Raman scattered data showed AROTEL approximately 1 K colder than sonde values. Comparisons between AROTEL and the Meteorological Measurement System (MMS) on NASA's ER-2 show AROTEL being from 2-3 K colder for altitudes ranging from 14 to 18 km. Temperature comparisons between AROTEL and the United Kingdom Meteorological Office's model showed differences of approximately 1 K below approximately 25 km and a very strong cold bias of approximately 12 K at altitudes between 30 and 35 km.

  12. Influence of temperature on the magnetic structure of HoCu2

    DEFF Research Database (Denmark)

    Smetana, S.; Sima, V.; Lebech, Bente

    1985-01-01

    Neutron powder diffraction measurements of orthorhombic HoCu2 are reported. The results confirm that the two cusps observed at ~7K and 10K in the magnetization data reflect a change of the magnetic structure and the Neel temperature. In the temperature range 7K......Neutron powder diffraction measurements of orthorhombic HoCu2 are reported. The results confirm that the two cusps observed at ~7K and 10K in the magnetization data reflect a change of the magnetic structure and the Neel temperature. In the temperature range 7K...

  13. Superconductivity in compressed lithium at 20 K.

    Science.gov (United States)

    Shimizu, Katsuya; Ishikawa, Hiroto; Takao, Daigoroh; Yagi, Takehiko; Amaya, Kiichi

    2002-10-10

    Superconductivity at high temperatures is expected in elements with low atomic numbers, based in part on conventional BCS (Bardeen-Cooper-Schrieffer) theory. For example, it has been predicted that when hydrogen is compressed to its dense metallic phase (at pressures exceeding 400 GPa), it will become superconducting with a transition temperature above room temperature. Such pressures are difficult to produce in a laboratory setting, so the predictions are not easily confirmed. Under normal conditions lithium is the lightest metal of all the elements, and may become superconducting at lower pressures; a tentative observation of a superconducting transition in Li has been previously reported. Here we show that Li becomes superconducting at pressures greater than 30 GPa, with a pressure-dependent transition temperature (T(c)) of 20 K at 48 GPa. This is the highest observed T(c) of any element; it confirms the expectation that elements with low atomic numbers will have high transition temperatures, and suggests that metallic hydrogen will have a very high T(c). Our results confirm that the earlier tentative claim of superconductivity in Li was correct.

  14. Temperature controlling system using embedded equipment

    Science.gov (United States)

    Rob, R.; Tirian, G. O.; Panoiu, C.

    2017-01-01

    Present paper describes the functionality of a temperature controlling system using PIC 18F45K22 microcontroller. The ambient temperature is acquired with LM35 analogue sensor. The microcontroller program is realized with MikroC compiler and it is able to control the speed of a cooling fan with dc motor. The speed can be increased in functioning with the increasing of the ambient temperature.

  15. Intermediate Temperature Water Heat Pipe Tests

    Science.gov (United States)

    Devarakonda, Angirasa; Xiong, Da-Xi; Beach, Duane E.

    2005-01-01

    Heat pipes are among the most promising technologies for space radiator systems. Water heat pipes are explored in the intermediate temperature range of 400 to above 500 K. The thermodynamic and thermo-physical properties of water are reviewed in this temperature range. Test data are reported for a copper-water heat pipe. The heat pipe was tested under different orientations. Water heat pipes show promise in this temperature range. Fabrication and testing issues are being addressed.

  16. Thin film diamond temperature sensor array for harsh aerospace environment

    Science.gov (United States)

    Aslam, M.; Masood, A.; Fredricks, R. J.; Tamor, M. A.

    1992-01-01

    The feasibility of using polycrystalline CVD diamond films as temperature sensors in harsh aerospace environment associated with hypersonic flights was tested using patterned diamond resistors, fabricated on flat or curved oxidized Si surfaces, as temperature sensors at temperatures between 20 and 1000 C. In this temperature range, the measured resistance was found to vary over 3 orders of magnitude and the temperature coefficient of resistance to change from 0.017/K to 0.003/K. After an annealing treatment, the resistance change was reproducible within 1 percent on the entire temperature range for short measuring times.

  17. Temperature hysteretic effect and its influence on colossal ...

    Indian Academy of Sciences (India)

    in magnetic fields up to 40 kOe have revealed anomalous temperature hysteretic effects both in 0 Oe and 20 kOe magnetic fields. The sharp ... This bulk sample also shows temperature hysteretic effects in resistivity [2,3]. No attempts has been made to study ... resistance ratio Rcool/Rwarm. Figure 2 shows the variation of.

  18. Nonlinear Corrections to Temperature in Computer Simulations of Complex Systems

    Science.gov (United States)

    2015-06-23

    at low temperatures, In Die Kunst of Phonons, eds. T. Paszkiewicz and K. Rapcewicz, Springer Verlag, 1994; pp. 105-112. 29 Schiener, B.; Böhmer, R...Time-dependent specific heat of crystals and glasses at low temperatures, pgs. 105-112 in Die Kunst of Phonons, eds. T. Paszkiewicz and K

  19. NMR study of niobium metal at high temperature

    Energy Technology Data Exchange (ETDEWEB)

    Shaham, M.

    1979-08-01

    The Knight shift and spin-lattice relaxation time of niobium were measured at temperatures extending from room temperature to 1700 K. A quantitative interpretation of T/sub 1/T data is presented, as well as a K-chi analysis to determine the various contributions to the magnetic susceptibility. The activation energy for diffusion, observed in the relaxation data, is also determined.

  20. 4H-SiC JFET Multilayer Integrated Circuit Technologies Tested Up to 1000 K

    Science.gov (United States)

    Spry, D. J.; Neudeck, P. G.; Chen, L.; Chang, C. W.; Lukco, D.; Beheim, G. M.

    2015-01-01

    Testing of semiconductor electronics at temperatures above their designed operating envelope is recognized as vital to qualification and lifetime prediction of circuits. This work describes the high temperature electrical testing of prototype 4H silicon carbide (SiC) junction field effect transistor (JFET) integrated circuits (ICs) technology implemented with multilayer interconnects; these ICs are intended for prolonged operation at temperatures up to 773K (500 C). A 50 mm diameter sapphire wafer was used in place of the standard NASA packaging for this experiment. Testing was carried out between 300K (27 C) and 1150K (877 C) with successful electrical operation of all devices observed up to 1000K (727 C).

  1. Analyses of D+ -> K(S)0 K+ and D+ -> K(S)0 pi +

    Energy Technology Data Exchange (ETDEWEB)

    Jessop, Colin P.

    2003-05-12

    Using data collected with the CLEO II detector at the Cornell Electron Storage Ring, we present new measurements of the branching fractions for D{sup +} {yields} K{sub S}K{sup +} and D{sup +} {yields} K{sub S}{pi}{sup +}. These results are combined with other CLEO measurements to extract the ratios of isospin amplitudes and phase shifts for D {yields} KK and D {yields} K{pi}.

  2. Measurements of the Branching Fractions of B0 --> K^*0K+K-, B0 --> K^*0pi+K-, B0 --> K*0K+pi-, and B0 --> K*0pi+pi-

    CERN Document Server

    Aubert, B; Karyotakis, Yu; Lees, J P; Poireau, V; Prudent, X; Tisserand, V; Zghiche, A; Garra Tico, J; Graugès-Pous, E; López, L; Palano, A; Pappagallo, M; Eigen, G; Stugu, B; Sun, L; Abrams, G S; Battaglia, M; Brown, D N; Button-Shafer, J; Cahn, R N; Groysman, Y; Jacobsen, R G; Kadyk, J A; Kerth, L T; Kolomensky, Yu G; Kukartsev, G; Lopes-Pegna, D; Lynch, G; Mir, L M; Orimoto, T J; Osipenkov, I L; Ronan, M T; Tackmann, K; Tanabé, T; Wenzel, W A; Del Amo-Sánchez, P; Hawkes, C M; Watson, A T; Koch, H; Schröder, T; Walker, D; Asgeirsson, D J; Çuhadar-Dönszelmann, T; Fulsom, B G; Hearty, C; Mattison, T S; McKenna, J A; Khan, A; Saleem, M; Teodorescu, L; Blinov, V E; Bukin, A D; Druzhinin, V P; Golubev, V B; Onuchin, A P; Serednyakov, S I; Skovpen, Yu I; Solodov, E P; Todyshev, K Yu; Bondioli, M; Curry, S; Eschrich, I; Kirkby, D; Lankford, A J; Lund, P; Mandelkern, M; Martin, E C; Stoker, D P; Abachi, S; Buchanan, C; Foulkes, S D; Gary, J W; Liu, F; Long, O; Shen, B C; Vitug, G M; Zhang, L; Paar, H P; Rahatlou, S; Sharma, V; Berryhill, J W; Campagnari, C; Cunha, A; Dahmes, B; Hong, T M; Kovalskyi, D; Richman, J D; Beck, T W; Eisner, A M; Flacco, C J; Heusch, C A; Kroseberg, J; Lockman, W S; Schalk, T; Schumm, B A; Seiden, A; Wilson, M G; Winstrom, L O; Chen, E; Cheng, C H; Fang, F; Hitlin, D G; Narsky, I; Piatenko, T; Porter, F C; Andreassen, R; Mancinelli, G; Meadows, B T; Mishra, K; Sokoloff, M D; Blanc, F; Bloom, P C; Chen, S; Ford, W T; Hirschauer, J F; Kreisel, A; Nagel, M; Nauenberg, U; Olivas, A; Smith, J G; Ulmer, K A; Wagner, S R; Zhang, J; Gabareen, A M; Soffer, A; Toki, W H; Wilson, R J; Winklmeier, F; Altenburg, D D; Feltresi, E; Hauke, A; Jasper, H; Merkel, J; Petzold, A; Spaan, B; Wacker, K; Klose, V; Kobel, M J; Lacker, H M; Mader, W F; Nogowski, R; Schubert, J; Schubert, K R; Schwierz, R; Sundermann, J E; Volk, A; Bernard, D; Bonneaud, G R; Latour, E; Lombardo, V; Thiebaux, C; Verderi, M; Clark, P J; Gradl, W; Muheim, F; Playfer, S; Robertson, A I; Watson, J E; Xie, Y; Andreotti, M; Bettoni, D; Bozzi, C; Calabrese, R; Cecchi, A; Cibinetto, G; Franchini, P; Luppi, E; Negrini, M; Petrella, A; Piemontese, L; Prencipe, E; Santoro, V; Anulli, F; Baldini-Ferroli, R; Calcaterra, A; De Sangro, R; Finocchiaro, G; Pacetti, S; Patteri, P; Peruzzi, I M; Piccolo, M; Rama, M; Zallo, A; Buzzo, A; Contri, R; Lo Vetere, M; Macri, M M; Monge, M R; Passaggio, S; Patrignani, C; Robutti, E; Santroni, A; Tosi, S; Chaisanguanthum, K S; Morii, M; Wu, J; Dubitzky, R S; Marks, J; Schenk, S; Uwer, U; Bard, D J; Dauncey, P D; Flack, R L; Nash, J A; Panduro-Vazquez, W; Tibbetts, M; Behera, P K; Chai, X; Charles, M J; Mallik, U; Cochran, J; Crawley, H B; Dong, L; Eyges, V; Meyer, W T; Prell, S; Rosenberg, E I; Rubin, A E; Gao, Y Y; Gritsan, A V; Guo, Z J; Lae, C K; Denig, A G; Fritsch, M; Schott, G; Arnaud, N; Bequilleux, J; D'Orazio, A; Davier, M; Grosdidier, G; Höcker, A; Lepeltier, V; Le Diberder, F; Lutz, A M; Pruvot, S; Rodier, S; Roudeau, P; Schune, M H; Serrano, J; Sordini, V; Stocchi, A; Wang, W F; Wormser, G; Lange, D J; Wright, D M; Bingham, I; Burke, J P; Chavez, C A; Fry, J R; Gabathuler, E; Gamet, R; Hutchcroft, D E; Payne, D J; Schofield, K C; Touramanis, C; Bevan, A J; George, K A; Di Lodovico, F; Sacco, R; Cowan, G; Flächer, H U; Hopkins, D A; Paramesvaran, S; Salvatore, F; Wren, A C; Brown, D N; Davis, C L; Allison, J; Bailey, D; Barlow, N R; Barlow, R J; Chia, Y M; Edgar, C L; Lafferty, G D; West, T J; Yi, J I; Anderson, J; Chen, C; Jawahery, A; Roberts, D A; Simi, G; Tuggle, J M; Blaylock, G; Dallapiccola, C; Hertzbach, S S; Li, X; Moore, T B; Salvati, E; Saremi, S; Cowan, R; Dujmic, D; Fisher, P H; Koeneke, K; Sciolla, G; Spitznagel, M; Taylor, F; Yamamoto, R K; Zhao, M; Zheng, Y; Mclachlin, S E; Patel, P M; Robertson, S H; Lazzaro, A; Palombo, F; Bauer, J M; Cremaldi, L; Eschenburg, V; Godang, R; Kroeger, R; Sanders, D A; Summers, D J; Zhao, H W; Brunet, S; Côté, D; Simard, M; Taras, P; Viaud, F B; Nicholson, H; De Nardo, Gallieno; Fabozzi, F; Lista, L; Monorchio, D; Sciacca, C; Baak, M A; Raven, G; Snoek, H L; Jessop, C P; Knoepfel, K J; LoSecco, J M; Benelli, G; Corwin, L A; Honscheid, K; Kagan, H; Kass, R; Morris, J P; Rahimi, A M; Regensburger, J J; Sekula, S J; Wong, Q K; Blount, N L; Brau, J E; Frey, R; Igonkina, O; Kolb, J A; Lu, M; Rahmat, R; Sinev, N B; Strom, D; Strube, J; Torrence, E; Gagliardi, N; Gaz, A; Margoni, M; Morandin, M; Pompili, A; Posocco, M; Rotondo, M; Simonetto, F; Stroili, R; Voci, C; Ben-Haim, E; Briand, H; Calderini, G; Chauveau, J; David, P; Del Buono, L; De La Vaissière, C; Hamon, O; Leruste, P; Malcles, J; Ocariz, J; Pérez, A; Prendki, J; Gladney, L; Biasini, M; Covarelli, R; Manoni, E; Angelini, C; Batignani, G; Bettarini, S; Carpinelli, M; Cenci, R; Cervelli, A; Forti, F; Giorgi, M A; Lusiani, A; Marchiori, G; Mazur, M A; Morganti, M; Neri, N; Paoloni, E; Rizzo, G; Walsh, J J; Biesiada, J; Elmer, P; Lau, Y P; Lü, C; Olsen, J; Smith, A J S; Telnov, A V; Baracchini, E; Bellini, F; Cavoto, G; Del Re, D; Di Marco, E; Faccini, R; Ferrarotto, F; Ferroni, F; Gaspero, M; Jackson, P D; Li Gioi, L; Mazzoni, M A; Morganti, S; Piredda, G; Polci, F; Renga, F; Voena, C; Ebert, M; Hartmann, T; Schröder, H; Waldi, R; Adye, T; Castelli, G; Franek, B; Olaiya, E O; Röthel, W; Wilson, F F; Emery, S; Escalier, M; Gaidot, A; Ganzhur, S F; Hamel de Monchenault, G; Kozanecki, W; Vasseur, G; Yéche, C; Zito, M; Chen, X R; Liu, H; Park, W; Purohit, M V; White, R M; Wilson, J R; Allen, M T; Aston, D; Bartoldus, R; Bechtle, P; Claus, R; Coleman, J P; Convery, M R; Dingfelder, J C; Dorfan, J; Dubois-Felsmann, G P; Dunwoodie, W; Field, R C; Glanzman, T; Gowdy, S J; Graham, M T; Grenier, P; Hast, C; Innes, W R; Kaminski, J; Kelsey, M H; Kim, H; Kim, P; Kocian, M L; Leith, D W G S; Li, S; Luitz, S; Lüth, V; Lynch, H L; MacFarlane, D B; Marsiske, H; Messner, R; Müller, D R; O'Grady, C P; Ofte, I; Perazzo, A; Perl, M; Pulliam, T; Ratcliff, B N; Roodman, A; Salnikov, A A; Schindler, R H; Schwiening, J; Snyder, A; Su, D; Sullivan, M K; Suzuki, K; Swain, S K; Thompson, J M; Vavra, J; Wagner, A P; Weaver, M; Wisniewski, W J; Wittgen, M; Wright, D H; Yarritu, A K; Yi, K; Young, C C; Ziegler, V; Burchat, P R; Edwards, A J; Majewski, S A; Miyashita, T S; Petersen, B A; Wilden, L; Ahmed, S; Alam, M S; Bula, R; Ernst, J A; Jain, V; Pan, B; Saeed, M A; Wappler, F R; Zain, S B; Krishnamurthy, M; Spanier, S M; Eckmann, R; Ritchie, J L; Ruland, A M; Schilling, C J; Schwitters, R F; Izen, J M; Lou, X C; Ye, S; Bianchi, F; Gallo, F; Gamba, D; Pelliccioni, M; Bomben, M; Bosisio, L; Cartaro, C; Cossutti, F; Della Ricca, G; Lanceri, L; Vitale, L; Azzolini, V; Lopez-March, N; Martínez-Vidal, F; Milanes, D A; Oyanguren, A; Albert, J; Banerjee, Sw; Bhuyan, B; Hamano, K; Kowalewski, R; Nugent, I M; Roney, J M; Sobie, R J; Harrison, P F; Ilic, J; Latham, T E; Mohanty, G B; Band, H R; Chen, X; Dasu, S; Flood, K T; Hollar, J J; Kutter, P E; Pan, Y; Pierini, M; Prepost, R; Wu, S L; Neal, H

    2007-01-01

    Branching fraction and asymmetry measurements of charmless $B^0\\to K^{*0}h^+_1h^-_2$ ($h_{1,2}$ = $K$, $\\pi$) decays are presented, using a data sample of 383 million $\\Upsilon(4S) \\to$ $B\\bar{B$} decays collected with the BaBar detector at the PEP-II asymmetric-energy $B$-meson factory at SLAC. The results are: ${\\cal B}$($B^0 \\to K^{*0}K^+ K^-)$ = (27.5 $\\pm$ 1.3 $\\pm$ 2.2) $\\times$ 10$^{-6}$, ${\\cal B}$($B^0$ $\\to$ $K^{*0}\\pi^+ K^-$) = (4.6 $\\pm$ 1.1 $\\pm$ 0.8) $\\times$ 10$^{-6}$ and ${\\cal B}$($B^0$ $\\to$ $K^{*0}\\pi^+\\pi^-$) = (54.5 $\\pm$ 2.9 $\\pm$ 4.3) $\\times$ 10$^{-6}$. The first errors quoted are statistical and the second are systematic. An upper limit is set for ${\\cal B}$($B^0$ $\\to$ $K^{*0}K^+ \\pi^-$) $<$ 2.2 $\\times$ 10$^{-6}$ at 90% confidence level.

  3. Hadronic molecular states from the K anti K* interaction

    Energy Technology Data Exchange (ETDEWEB)

    Lue, Pei-Liang; He, Jun [Chinese Academy of Sciences, Theoretical Physics Division, Institute of Modern Physics, Lanzhou (China); Institute of Modern Physics of CAS and Lanzhou University, Research Center for Hadron and CSR Physics, Lanzhou (China)

    2016-12-15

    In this work, the K anti K* interaction is studied in a quasipotential Bethe-Salpeter equation approach combined with the one-boson-exchange model. With the help of the hidden-gauge Lagrangian, the exchanges of pseudoscalar mesons (π and η) and vector mesons (ρ, ω and φ) are considered to describe the K anti K* interaction. Besides the direct vector-meson exchange which can be related to the Weinberg-Tomozawa term, pseudoscalar-meson exchanges also play important roles in the mechanism of the K anti K* interaction. The poles of scattering amplitude are searched to find the molecular states produced from the K anti K* interaction. In the case of quantum number I{sup G}(J{sup PC}) = 0{sup +}(1{sup ++}), a pole is found with a reasonable cutoff, which can be related to the f{sub 1}(1285) in experiment. Another bound state with 0{sup -}(1{sup +-}) is also produced from the K anti K* interaction, which can be related to the h{sub 1}(1380). In the isovector sector, the interaction is much weaker and a bound state with 1{sup +}(1{sup +}) relevant to the b{sub 1}(1235) is produced but at a larger cutoff. Our results suggest that in the hadronic molecular state picture the f{sub 1}(1285) and b{sub 1}(1235) are the strange partners of the X(3872) and Z{sub c}(3900), respectively. (orig.)

  4. Vitamin K and bone health.

    Science.gov (United States)

    Hamidi, Maryam S; Gajic-Veljanoski, Olga; Cheung, Angela M

    2013-01-01

    Vitamin K has been purported to play an important role in bone health. It is required for the gamma-carboxylation of osteocalcin (the most abundant noncollagenous protein in bone), making osteocalcin functional. There are 2 main forms (vitamin K1 and vitamin K2), and they come from different sources and have different biological activities. Epidemiologic studies suggest a diet high in vitamin K is associated with a lower risk of hip fractures in aging men and women. However, randomized controlled trials of vitamin K1 or K2 supplementation in white populations did not increase bone mineral density at major skeletal sites. Supplementation with vitamin K1 and K2 may reduce the risk of fractures, but the trials that examined fractures as an outcome have methodological limitations. Large well-designed trials are needed to compare the efficacies of vitamin K1 and K2 on fractures. We conclude that currently there is not enough evidence to recommend the routine use of vitamin K supplements for the prevention of osteoporosis and fractures in postmenopausal women. Copyright © 2013 The International Society for Clinical Densitometry. Published by Elsevier Inc. All rights reserved.

  5. Dielectric properties measurement system at cryogenic temperatures and microwave frequencies

    Energy Technology Data Exchange (ETDEWEB)

    Molla, J.; Ibarra, A.; Margineda, J.; Zamarro, J. M.; Hernandez, A.

    1994-07-01

    A system based on the resonant cavity method has been developed to measure the permittivity and loss tangent at 12-18 GHz over the temperature range 80 K to 300 K. Changes of permittivity as low as 0.01 % in the range 1 to 30, and 3 x 10{sup 6} for loss tangent values below 10{sup 2}, can be obtained without requiring temperature stability. The thermal expansion coefficient and resistivity factor of copper have been measured between 80 K and 300 K. Permittivity of sapphire and loss tangent of alumina of 99.9 % purity in the same temperature range are presented. (Author) 23 refs.

  6. Search for the decay B^0 --> K^0_S K^0_S K^0_L

    Energy Technology Data Exchange (ETDEWEB)

    Aubert, B.

    2006-06-27

    The authors present the first search for the decay B{sup 0} {yields} K{sub S}{sup 0} K{sub S}{sup 0} K{sub L}{sup 0} using a data sample of 232 million B{bar B} pairs. They find no statistically significant evidence for the non-resonant component of this decay. Our central value for the branching fraction, assuming the tru Dalitz distribution is uniform and excluding the {phi} resonance, is {Beta}(B{sup 0} {yields} K{sub S}{sup 0} K{sub S}{sup 0} K{sub L}{sup 0}) = (2.4{sub -2.5}{sup +2.7} {+-} 0.6) x 10{sup -6} where the errors are statistical and systematic, respectively. They set a single-side Bayesian upper limit of {Beta}(B{sup 0} {yields} K{sub S}{sup 0} K{sub S}{sup 0} K{sub L}{sup 0}) < 6.4 x 10{sup -6} at 90% confidence level using a uniform prior probability for physical values. Assuming the worst-case true Dalitz distribution, where the signal is entirely in the region of lowest efficiency, the 90% confidence level upper limit is {Beta}(B{sup 0} {yields} K{sub S}{sup 0} K{sub S}{sup 0} K{sub L}{sup 0}) < 14 x 10{sup -6}.

  7. A 4 K tactical cryocooler using reverse-Brayton machines

    Science.gov (United States)

    Zagarola, M.; Cragin, K.; McCormick, J.; Hill, R.

    2017-12-01

    Superconducting electronics and spectral-spatial holography have the potential to revolutionize digital communications, but must operate at cryogenic temperatures, near 4 K. Liquid helium is undesirable for military missions due to logistics and scarcity, and commercial low temperature cryocoolers are unable to meet size, weight, power, and environmental requirements for many missions. To address this need, Creare is developing a reverse turbo-Brayton cryocooler that provides refrigeration at 4.2 K and rejects heat at 77 K to an upper-stage cryocooler or through boil-off of liquid nitrogen. The cooling system is predicted to reduce size, weight, and input power by at least an order of magnitude as compared to the current state-of-the-art 4.2 K cryocooler. For systems utilizing nitrogen boil-off, the boil-off rate is reasonable. This paper reviews the design of the cryocooler, the key components, and component test results.

  8. Thermophysical properties of lignocellulose: a cell-scale study down to 41 K.

    Directory of Open Access Journals (Sweden)

    Zhe Cheng

    Full Text Available Thermal energy transport is of great importance in lignocellulose pyrolysis for biofuels. The thermophysical properties of lignocellulose significantly affect the overall properties of bio-composites and the related thermal transport. In this work, cell-scale lignocellulose (mono-layer plant cells is prepared to characterize their thermal properties from room temperature down to ∼ 40 K. The thermal conductivities of cell-scale lignocellulose along different directions show a little anisotropy due to the cell structure anisotropy. It is found that with temperature going down, the volumetric specific heat of the lignocellulose shows a slower decreasing trend against temperature than microcrystalline cellulose, and its value is always higher than that of microcrystalline cellulose. The thermal conductivity of lignocellulose decreases with temperature from 243 K to 317 K due to increasing phonon-phonon scatterings. From 41 K to 243 K, the thermal conductivity rises with temperature and its change mainly depends on the heat capacity's change.

  9. Measuring nanowire thermal conductivity at high temperatures

    Science.gov (United States)

    Wang, Xiaomeng; Yang, Juekuan; Xiong, Yucheng; Huang, Baoling; Xu, Terry T.; Li, Deyu; Xu, Dongyan

    2018-02-01

    This work extends the micro-thermal-bridge method for thermal conductivity measurements of nanowires to high temperatures. The thermal-bridge method, based on a microfabricated device with two side-by-side suspended membranes with integrated platinum resistance heaters/thermometers, has been used to determine thermal conductivity of various nanowires/nanotubes/nanoribbons at relatively low temperatures. However, to date, thermal conductivity characterization of nanowires at temperatures above 600 K has seldom been reported presumably due to several technical difficulties including the instability of the microfabricated thermometers, radiation heat loss, and the effect of the background conductance on the measurement. Here we report on our attempt to address the aforementioned challenges and demonstrate thermal conductivity measurement of boron nanoribbons up to 740 K. To eliminate high temperature resistance instability, the device is first annealed at 1023 K for 5 min in an argon atmosphere. Two radiation shields are installed in the measurement chamber to minimize radiation heat loss from the measurement device to the surroundings; and the temperature of the device at each set point is calibrated by an additional thermocouple directly mounted on the chip carrier. The effect of the background conductance is eliminated by adopting a differential measurement scheme. With all these modifications, we successfully measured the thermal conductivity of boron nanoribbons over a wide temperature range from 27 K to 740 K. The measured thermal conductivity increases monotonically with temperature and reaches a plateau of ~2.5 W m‑1 K‑1 at approximately 400 K, with no clear signature of Umklapp scattering observed in the whole measurement temperature range.

  10. Superhigh Temperatures and Acoustic Cavitation

    CERN Document Server

    Belyaev, V B; Miller, M B; Sermyagin, A V; Topolnikov, A S

    2003-01-01

    The experimental results on thermonuclear synthesis under acoustic cavitation have been analyzed with the account of the latest data and their discussion. The analysis testifies that this avenue of research is a very promising one. The numerical calculations of the D(d, n)^{3}He reaction rate in the deuterated acetone (C_{3}D_{6}O) under the influence of ultrasound depending on T environment temperature within the range T=249-295 K have been carried out within the framework of hydrodynamic model. The results show that it is possible to improve substantially the effect/background relationship in experiments by decreasing the fluid temperature twenty-thirty degrees below zero.

  11. The thermal conductivity of high modulus Zylon fibers between 400 mK and 4 K

    Science.gov (United States)

    Wikus, Patrick; Figueroa-Feliciano, Enectalí; Hertel, Scott A.; Leman, Steven W.; McCarthy, Kevin A.; Rutherford, John M.

    2008-11-01

    Zylon is a synthetic polyurethane polymer fiber featuring very high mechanical strength. Measurements of the thermal conductivity λZ(T) of high modulus Zylon fibers at temperatures between 400 mK and 4 K were performed to assess if they can be successfully employed in the design of high performance suspension systems for cold stages of adiabatic demagnetization refrigerators. The linear mass density of the yarn used in these measurements amounts to 3270 dtex, which is also a measure for the yarn's cross section. The experimental data for the thermal conductivity was fitted to a function of the form λZ=(1010±30)·TpWmmdtexK. This result was normalized to the breaking strength of the fibers and compared with Kevlar. It shows that Kevlar outperforms Zylon in the investigated temperature range. At 1.5 K, the thermal conductivity integral of Zylon yarn is twice as high as the thermal conductivity integral of Kevlar yarn with the same breaking strength. A linear mass density of 1 tex is equivalent to a yarn mass of 1 g/km. High modulus Zylon has a density of 1.56 g/cm 3.

  12. Observation of the Decay B+ --> K+K-pi+

    CERN Document Server

    Aubert, B; Boutigny, D; Karyotakis, Yu; Lees, J P; Poireau, V; Prudent, X; Tisserand, V; Zghiche, A; Garra Tico, J; Graugès-Pous, E; López, L; Palano, A; Pappagallo, M; Eigen, G; Stugu, B; Sun, L; Abrams, G S; Battaglia, M; Brown, D N; Button-Shafer, J; Cahn, R N; Groysman, Y; Jacobsen, R G; Kadyk, J A; Kerth, L T; Kolomensky, Yu G; Kukartsev, G; Lopes-Pegna, D; Lynch, G; Mir, L M; Orimoto, T J; Osipenkov, I L; Ronan, M T; Tackmann, K; Tanabé, T; Wenzel, W A; Del Amo-Sánchez, P; Hawkes, C M; Watson, A T; Held, T; Koch, H; Pelizaeus, M; Schröder, T; Steinke, M; Walker, D; Asgeirsson, D J; Çuhadar-Dönszelmann, T; Fulsom, B G; Hearty, C; Mattison, T S; McKenna, J A; Khan, A; Saleem, M; Teodorescu, L; Blinov, V E; Bukin, A D; Druzhinin, V P; Golubev, V B; Onuchin, A P; Serednyakov, S I; Skovpen, Yu I; Solodov, E P; Todyshev, K Yu; Bondioli, M; Curry, S; Eschrich, I; Kirkby, D; Lankford, A J; Lund, P; Mandelkern, M; Martin, E C; Stoker, D P; Abachi, S; Buchanan, C; Foulkes, S D; Gary, J W; Liu, F; Long, O; Shen, B C; Zhang, L; Paar, H P; Rahatlou, S; Sharma, V; Berryhill, J W; Campagnari, C; Cunha, A; Dahmes, B; Hong, T M; Kovalskyi, D; Richman, J D; Beck, T W; Eisner, A M; Flacco, C J; Heusch, C A; Kroseberg, J; Lockman, W S; Schalk, T; Schumm, B A; Seiden, A; Wilson, M G; Winstrom, L O; Chen, E; Cheng, C H; Fang, F; Hitlin, D G; Narsky, I; Piatenko, T; Porter, F C; Andreassen, R; Mancinelli, G; Meadows, B T; Mishra, K; Sokoloff, M D; Blanc, F; Bloom, P C; Chen, S; Ford, W T; Hirschauer, J F; Kreisel, A; Nagel, M; Nauenberg, U; Olivas, A; Smith, J G; Ulmer, K A; Wagner, S R; Zhang, J; Gabareen, A M; Soffer, A; Toki, W H; Wilson, R J; Winklmeier, F; Altenburg, D D; Feltresi, E; Hauke, A; Jasper, H; Merkel, J; Petzold, A; Spaan, B; Wacker, K; Klose, V; Kobel, M J; Lacker, H M; Mader, W F; Nogowski, R; Schubert, J; Schubert, K R; Schwierz, R; Sundermann, J E; Volk, A; Bernard, D; Bonneaud, G R; Latour, E; Lombardo, V; Thiebaux, C; Verderi, M; Clark, P J; Gradl, W; Muheim, F; Playfer, S; Robertson, A I; Watson, J E; Xie, Y; Andreotti, M; Bettoni, D; Bozzi, C; Calabrese, R; Cecchi, A; Cibinetto, G; Franchini, P; Luppi, E; Negrini, M; Petrella, A; Piemontese, L; Prencipe, E; Santoro, V; Anulli, F; Baldini-Ferroli, R; Calcaterra, A; De Sangro, R; Finocchiaro, G; Pacetti, S; Patteri, P; Peruzzi, I M; Piccolo, M; Rama, M; Zallo, A; Buzzo, A; Contri, R; Lo Vetere, M; Macri, M M; Monge, M R; Passaggio, S; Patrignani, C; Robutti, E; Santroni, A; Tosi, S; Chaisanguanthum, K S; Morii, M; Wu, J; Dubitzky, R S; Marks, J; Schenk, S; Uwer, U; Bard, D J; Dauncey, P D; Flack, R L; Nash, J A; Panduro-Vazquez, W; Tibbetts, M; Behera, P K; Chai, X; Charles, M J; Mallik, U; Ziegler, V; Cochran, J; Crawley, H B; Dong, L; Eyges, V; Meyer, W T; Prell, S; Rosenberg, E I; Rubin, A E; Gao, Y Y; Gritsan, A V; Guo, Z J; Lae, C K; Denig, A G; Fritsch, M; Schott, G; Arnaud, N; Bequilleux, J; D'Orazio, A; Davier, M; Grosdidier, G; Höcker, A; Lepeltier, V; Le Diberder, F; Lutz, A M; Pruvot, S; Rodier, S; Roudeau, P; Schune, M H; Serrano, J; Sordini, V; Stocchi, A; Wang, W F; Wormser, G; Lange, D J; Wright, D M; Bingham, I; Burke, J P; Chavez, C A; Forster, I J; Fry, J R; Gabathuler, E; Gamet, R; Hutchcroft, D E; Payne, D J; Schofield, K C; Touramanis, C; Bevan, A J; George, K A; Di Lodovico, F; Menges, W; Sacco, R; Cowan, G; Flächer, H U; Hopkins, D A; Paramesvaran, S; Salvatore, F; Wren, A C; Brown, D N; Davis, C L; Allison, J; Barlow, N R; Barlow, R J; Chia, Y M; Edgar, C L; Lafferty, G D; West, T J; Yi, J I; Anderson, J; Chen, C; Jawahery, A; Roberts, D A; Simi, G; Tuggle, J M; Blaylock, G; Dallapiccola, C; Hertzbach, S S; Li, X; Moore, T B; Salvati, E; Saremi, S; Cowan, R; Dujmic, D; Fisher, P H; Koeneke, K; Sciolla, G; Sekula, S J; Spitznagel, M; Taylor, F; Yamamoto, R K; Zhao, M; Zheng, Y; Mclachlin, S E; Patel, P M; Robertson, S H; Lazzaro, A; Palombo, F; Bauer, J M; Cremaldi, L; Eschenburg, V; Godang, R; Kroeger, R; Sanders, D A; Summers, D J; Zhao, H W; Brunet, S; Côté, D; Simard, M; Taras, P; Viaud, F B; Nicholson, H; De Nardo, Gallieno; Fabozzi, F; Lista, L; Monorchio, D; Sciacca, C; Baak, M A; Raven, G; Snoek, H L; Jessop, C P; Knoepfel, K J; LoSecco, J M; Benelli, G; Corwin, L A; Honscheid, K; Kagan, H; Kass, R; Morris, J P; Rahimi, A M; Regensburger, J J; Wong, Q K; Blount, N L; Brau, J E; Frey, R; Igonkina, O; Kolb, J A; Lu, M; Rahmat, R; Sinev, N B; Strom, D; Strube, J; Torrence, E; Gagliardi, N; Gaz, A; Margoni, M; Morandin, M; Pompili, A; Posocco, M; Rotondo, M; Simonetto, F; Stroili, R; Voci, C; Ben-Haim, E; Briand, H; Calderini, G; Chauveau, J; David, P; Del Buono, L; De La Vaissière, C; Hamon, O; Leruste, P; Malcles, J; Ocariz, J; Pérez, A; Prendki, J; Gladney, L; Biasini, M; Covarelli, R; Manoni, E; Angelini, C; Batignani, G; Bettarini, S; Carpinelli, M; Cenci, R; Cervelli, A; Forti, F; Giorgi, M A; Lusiani, A; Marchiori, G; Mazur, M A; Morganti, M; Neri, N; Paoloni, E; Rizzo, G; Walsh, J J; Haire, M; Biesiada, J; Elmer, P; Lau, Y P; Lü, C; Olsen, J; Smith, A J S; Telnov, A V; Baracchini, E; Bellini, F; Cavoto, G; Del Re, D; Di, E; Marco; Faccini, R; Ferrarotto, F; Ferroni, F; Gaspero, M; Jackson, P D; Li Gioi, L; Mazzoni, M A; Morganti, S; Piredda, G; Polci, F; Renga, F; Voena, C; Ebert, M; Hartmann, T; Schröder, H; Waldi, R; Adye, T; Castelli, G; Franek, B; Olaiya, E O; Ricciardi, S; Röthel, W; Wilson, F F; Emery, S; Escalier, M; Gaidot, A; Ganzhur, S F; Hamel de Monchenault, G; Kozanecki, W; Vasseur, G; Yéche, C; Zito, M; Chen, X R; Liu, H; Park, W; Purohit, M V; Wilson, J R; Allen, M T; Aston, D; Bartoldus, R; Bechtle, P; Berger, N; Claus, R; Coleman, J P; Convery, M R; Dingfelder, J C; Dorfan, J; Dubois-Felsmann, G P; Dunwoodie, W; Field, R C; Glanzman, T; Gowdy, S J; Graham, M T; Grenier, P; Hast, C; Hrynóva, T; Innes, W R; Kaminski, J; Kelsey, M H; Kim, H; Kim, P; Kocian, M L; Leith, D W G S; Li, S; Luitz, S; Lüth, V; Lynch, H L; MacFarlane, D B; Marsiske, H; Messner, R; Müller, D R; O'Grady, C P; Ofte, I; Perazzo, A; Perl, M; Pulliam, T; Ratcliff, B N; Roodman, A; Salnikov, A A; Schindler, R H; Schwiening, J; Snyder, A; Stelzer, J; Su, D; Sullivan, M K; Suzuki, K; Swain, S K; Thompson, J M; Vavra, J; Van Bakel, N; Wagner, A P; Weaver, M; Wisniewski, W J; Wittgen, M; Wright, D H; Yarritu, A K; Yi, K; Young, C C; Burchat, P R; Edwards, A J; Majewski, S A; Petersen, B A; Wilden, L; Ahmed, S; Alam, M S; Bula, R; Ernst, J A; Jain, V; Pan, B; Saeed, M A; Wappler, F R; Zain, S B; Krishnamurthy, M; Spanier, S M; Eckmann, R; Ritchie, J L; Ruland, A M; Schilling, C J; Schwitters, R F; Izen, J M; Lou, X C; Ye, S; Bianchi, F; Gallo, F; Gamba, D; Pelliccioni, M; Bomben, M; Bosisio, L; Cartaro, C; Cossutti, F; Della Ricca, G; Lanceri, L; Vitale, L; Azzolini, V; Lopez-March, N; Martínez-Vidal, F; Milanes, D A; Oyanguren, A; Albert, J; Banerjee, Sw; Bhuyan, B; Hamano, K; Kowalewski, R; Nugent, I M; Roney, J M; Sobie, R J; Gershon, T J; Harrison, P F; Ilic, J; Latham, T E; Mohanty, G B; Band, H R; Chen, X; Dasu, S; Flood, K T; Hollar, J J; Kutter, P E; Pan, Y; Pierini, M; Prepost, R; Wu, S L; Neal, H

    2007-01-01

    We report the observation of charmless hadronic decays of charged B mesons to the final state K+K-pi+. Using a data sample of 347.5 fb^-1 collected at the Y(4S) resonance with the BABAR detector, we observe 429+/-43 signal events with a significance of 9.6 sigma. We measure the inclusive branching fraction BF(B+ --> K+K-pi+) = [5.0+/-0.5(stat.)+/-0.5(syst.)]x10^-6. Inspection of the Dalitz plot of signal candidates shows a broad structure peaking near 1.5 GeV/c^2 in the K+K- invariant mass distribution. We find the direct CP asymmetry to be consistent with zero.

  13. Phase diagrams and physicochemical properties of Li+,K+(Rb+)//borate-H2O systems at 323 K

    Science.gov (United States)

    Feng, Shan; Yu, Xudong; Cheng, Xinglong; Zeng, Ying

    2017-11-01

    The phase and physicochemical properties diagrams of Li+,K+(Rb+)//borate-H2O systems at 323 K were constructed using the experimentally measured solubilities, densities, and refractive indices. The Schreinemakers' wet residue method and the X-ray diffraction were used for the determination of the compositions of solid phase. Results show that these two systems belong to the hydrate I type, with no solid solution or double salt formation. The borate phases formed in our experiments are RbB5O6(OH)4 · 2H2O, Li2B4O5(OH)4 · H2O, and K2B4O5(OH)4 · 2H2O. Comparison between the stable phase diagrams of the studied system at 288, 323, and 348 K show that in this temperature range, the crystallization form of salts do not changed. With the increase in temperature, the crystallization field of Li2B4O5(OH)4 · H2O salt at 348 K is obviously larger than that at 288 K. In the Li+,K+(Rb+)//borate-H2O systems, the densities and refractive indices of the solutions (at equilibrium) increase along with the mass fraction of K2B4O7 (Rb2B4O7), and reach the maximum values at invariant point E.

  14. Effect of substrate temperature on electrical and magnetic properties ...

    Indian Academy of Sciences (India)

    Home; Journals; Pramana – Journal of Physics; Volume 58; Issue 5-6. Effect of substrate temperature on electrical and magnetic properties of epitaxial La 1 − Pb MnO3 films. Ajay Singh D K Aswal Shashwati Sen K Shah L C Gupta S K Gupta V C Sahni. Colossal Magnetoresistance & Other Materials Volume 58 Issue ...

  15. Finite-Size Scaling in Random K-SAT Problems

    Science.gov (United States)

    Ha, Meesoon; Lee, Sang Hoon; Jeon, Chanil; Jeong, Hawoong

    2010-03-01

    We propose a comprehensive view of threshold behaviors in random K-satisfiability (K-SAT) problems, in the context of the finite-size scaling (FSS) concept of nonequilibrium absorbing phase transitions using the average SAT (ASAT) algorithm. In particular, we focus on the value of the FSS exponent to characterize the SAT/UNSAT phase transition, which is still debatable. We also discuss the role of the noise (temperature-like) parameter in stochastic local heuristic search algorithms.

  16. Observation of double phi-meson production in the central region for the reactions. pi. /sup +/p->. pi. /sup +/(K/sup +/K/sup +/K/sup -/K/sup -/)p and pp->p(K/sup +/K/sup +/K/sup -/K/sup -/)p at 85 GeV/c

    Energy Technology Data Exchange (ETDEWEB)

    Armstrong, T.A.; French, B.R.; Bloodworth, I.J.; Carney, J.N.; Kinson, J.B.; Print, I.C.; Villalobos Baillie, O.; Votruba, M.F.; Ghidini, B.; Lenti, V.

    1986-01-09

    The reactions ..pi../sup +/p->..pi../sup +/(K/sup +/K/sup +/K/sup -/K/sup -/)p and pp->p(K/sup +/K/sup +/K/sup -/K/sup -/)p in which the K/sup +/K/sup +/K/sup -/K/sup -/ system is centrally produced have been studied at 85 GeV/c. Evidence is found for phiphi production. The relative rates for production of phiphi, phiK/sup +/K/sup -/ and K/sup +/K/sup +/K/sup -/K/sup -/ have been determined. (orig.).

  17. Monitoring of a 1 kWp Solar Photovoltaic System

    Science.gov (United States)

    Malek, M. F.; Zainuddin, H.; Rejab, S. N. M.; Shaari, S. N.; Shaari, S.; Omar, A. M.; Rusop, M.

    2009-06-01

    A 1 kWp `stand alone' PV system consists of 4 module (2 BP SX75U module and 2 BP 275F module), inverter, 2 thermocouple, 3 voltage sensor, 3 current sensor, 4 battery and data logger (Data Taker DT80) has been set up. This research involve nine parameters which are irradiance (Ia), ambient temperature (Tamb), module temperature (Tmod), module voltage (Vmod), battery voltage (Vbat), load voltage (Vload), module current (Imod), battery current (Ibat) and load current (Iload). All parameters were measured using the equipments and sensors that connected directly to data logger (Data Taker DT80) to interpret and show the data on computer using the Delogger sofware. The data then was transferred into the computer and analyzed using the Deview and Microsoft Excel software to determine the performance indices for the stand alone PV system. From the analysis a few performance indices were determined. The range of daily solar irradiation is between 2.20 kWhm-2 to 4.00 kWhm-2, while the range of total global irradiation is between 5.76 kWh to 10.48 kWh. For daily total energy yield, the range is between 0.23 kWh d-1 to 0.28 kWh d-1. The range for clearness index is between 0.49% to 0.89%. The range for final yield is between 0.77 kWh d-1 kWp-1 to 0.93 kWhd-1 kWp-1 while the range of array efficiency is between 2.53% to 4.65%. Lastly, the range of the performance ratio is between 22.08% to 40.58%.

  18. Low Temperature Operation of a Switching Power Converter

    Science.gov (United States)

    Anglada-Sanchez, Carlos R.; Perez-Feliciano, David; Ray, Biswajit

    1997-01-01

    The low temperature operation of a 48 W, 50 kHz, 36/12 V pulse width modulated (PWM) buck de-de power converter designed with standard commercially available components and devices is reported. The efficiency of the converter increased from 85.6% at room temperature (300 K) to 92.0% at liquid nitrogen temperature (77 K). The variation of power MOSFET, diode rectifier, and output filter inductor loss with temperature is discussed. Relevant current, voltage. and power waveforms are also included.

  19. Thermal conductance characterization of a pressed copper rope strap between 0.13 K and 10 K

    Science.gov (United States)

    Dhuley, R. C.; Ruschman, M.; Link, J. T.; Eyre, J.

    2017-09-01

    Mechanically pressing the ends of a copper braid in solid copper is an effective way of constructing solderless conductive straps for cryogenic applications. In this paper we present thermal conductance data of such a copper strap measured using the two-heater one-thermometer method. The measurements span a wide temperature range of 0.13-10 K applicable to a variety of cryogenic systems employing liquid helium, pulse tube coolers, adiabatic demagnetization refrigerators, and others. Above ≈1.5 K, the braid thermal conductivity dominates the strap conductance resulting in a near-linear dependence with temperature. The variation with temperature below ≈1.5 K is near-quadratic indicating dominance of the pressed contact conductance at the strap ends. Electron-beam welding the braid to the strap ends is shown to be a promising solution for improving sub-Kelvin thermal conductance of the strap.

  20. Experimental progress of a 4K VM/PT hybrid cryocooler for pre-cooling 1K sorption cooler

    Science.gov (United States)

    Pan, Changzhao; Zhang, Tong; Wang, Jue; Chen, Liubiao; Guo, Jia; Zhou, Yuan; Wang, Junjie

    2017-12-01

    Sub-kelvin refrigerator has many applications in space detector and manned space station, such as for the transition-edge superconducting (TES) bolometers operated in the 50 mK range. In order to meet the requirement of space applications, the high efficient, vibration free and high stability refrigerator need to be designed. VM/PT hybrid cryocooler is a new type cryocooler capable of attaining temperature below 4K. As a low frequency Stirling type cryocooler, it has the advantages of high stability and high efficiency. Combined with the vibration free sorption cooler and ADR refrigerator, a novel sub-kelvin cooling chain can be designed for the TES bolometer. This paper presents the recent experimental progress of the 4K VM/PT hybrid cryocooler in our laboratory. By optimizing of regenerators, phase shifters and heat exchangers, a lowest temperature of 2.6K was attained. Based on this cryocooler, a preliminary sorption cooler could be designed.

  1. Amplitude analysis of D0->K+K-pi+pi-

    CERN Document Server

    Artuso, M; Mountain, R; Skwarnicki, T; Stone, S; Zhang, L M; Gershon, T; Bonvicini, G; Cinabro, D; Lincoln, A; Smith, M J; Zhou, P; Zhu, J; Naik, P; Rademacker, J; Asner, D M; Edwards, K W; Randrianarivony, K; Tatishvili, G; Briere, R A; Vogel, H; Onyisi, P U E; Rosner, J L; Alexander, J P; Cassel, D G; Das, S; Ehrlich, R; Gibbons, L; Gray, S W; Hartill, D L; Heltsley, B K; Kreinick, D L; Kuznetsov, V E; Patterson, J R; Peterson, D; Riley, D; Ryd, A; Sadoff, A J; Shi, X; Sun, W M; Yelton, J; Rubin, P; Lowrey, N; Mehrabyan, S; Selen, M; Wiss, J; Libby, J; Kornicer, M; Mitchell, R E; Besson, D; Pedlar, T K; Cronin-Hennessy, D; Hietala, J; Dobbs, S; Metreveli, Z; Seth, K K; Tomaradze, A; Xiao, T; Martin, L; Powell, A; Spradlin, P; Wilkinson, G; Ge, J Y; Miller, D H; Shipsey, I P J; Xin, B; Adams, G S; Napolitano, J; Ecklund, K M; Insler, J; Muramatsu, H; Park, C S; Pearson, L J; Thorndike, E H; Ricciardi, S; Thomas, C

    2012-01-01

    The first flavor-tagged amplitude analysis of the decay D0 to the self-conjugate final state K+K-pi+pi- is presented. Data from the CLEO II.V, CLEO III, and CLEO-c detectors are used, from which around 3000 signal decays are selected. The three most significant amplitudes, which contribute to the model that best fits the data, are phirho0, K1(1270)+-K-+, and non-resonant K+K-pi+pi-. Separate amplitude analyses of D0 and D0-bar candidates indicate no CP violation among the amplitudes at the level of 5% to 30% depending on the mode. In addition, the sensitivity to the CP-violating parameter gamma/phi3 of a sample of 2000 B+ -> D0-tilde(K+K-pi+pi-)K+ decays, where D0-tilde is a D0 or D0-bar, collected at LHCb or a future flavor facility, is estimated to be (11.3 +/- 0.3) degrees using the favored model.

  2. Central exclusive K+K- production in CDF

    Science.gov (United States)

    Gioiosa, Antonio

    2017-03-01

    We present new CDF data on exclusive K+ K- and p p ¯ production. Data were taken at √{s }=1960 GeV and 900 GeV in low pile-up conditions. Events were selected with exactly two well-measured central tracks with pT > 300 MeV/c and |η| JPC = 0+(even)++. Kaons and (anti-)protons were identified using a barrel of time-of-flight scintillation counters. The mass spectrum M(K+ K-) shows evidence for novel resonance structure in the region 1500 - 1800 MeV/c2.

  3. Surface Temperatures on Titan During Northern Winter and Spring

    Science.gov (United States)

    Jennings, D. E.; Cottini, V.; Nixon, C. A.; Achterberg, R. K.; Flasar, F. M.; Kunde ,V. G.; Romani, P. N.; Samuelson, R. E.; Mamoutkine, A.; Gorius, N. J. P.; hide

    2016-01-01

    Meridional brightness temperatures were measured on the surface of Titan during the 2004-2014 portion of the Cassini mission by the Composite Infrared Spectrometer. Temperatures mapped from pole to pole during five two year periods show a marked seasonal dependence. The surface temperature near the south pole over this time decreased by 2 K from 91.7 plus or minus 0.3 to 89.7 plus or minus 0.5 K while at the north pole the temperature increased by 1 K from 90.7 plus or minus 0.5 to 91.5 plus or minus 0.2 K. The latitude of maximum temperature moved from 19 S to 16 N, tracking the subsolar latitude. As the latitude changed, the maximum temperature remained constant at 93.65 plus or minus 0.15 K. In 2010 our temperatures repeated the north-south symmetry seen by Voyager one Titan year earlier in 1980. Early in the mission, temperatures at all latitudes had agreed with GCM predictions, but by 2014 temperatures in the north were lower than modeled by 1 K. The temperature rise in the north may be delayed by cooling of sea surfaces and moist ground brought on by seasonal methane precipitation and evaporation.

  4. SURFACE TEMPERATURES ON TITAN DURING NORTHERN WINTER AND SPRING

    Energy Technology Data Exchange (ETDEWEB)

    Jennings, D. E.; Cottini, V.; Nixon, C. A.; Achterberg, R. K.; Flasar, F. M.; Kunde, V. G.; Romani, P. N.; Samuelson, R. E. [Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Mamoutkine, A. [ADNET Systems, Inc., Bethesda, MD 20817 (United States); Gorius, N. J. P. [The Catholic University of America, Washington, DC 20064 (United States); Coustenis, A. [Laboratoire d’Etudes Spatiales et d’Instrumentation en Astrophysique (LESIA), Observatoire de Paris, CNRS, UPMC Univ. Paris 06, Univ. Paris-Diderot, 5, place Jules Janssen, F-92195 Meudon Cedex (France); Tokano, T., E-mail: donald.e.jennings@nasa.gov [Universität zu Köln, Albertus-Magnus-Platz, D-50923 Köln (Germany)

    2016-01-01

    Meridional brightness temperatures were measured on the surface of Titan during the 2004–2014 portion of the Cassini mission by the Composite Infrared Spectrometer. Temperatures mapped from pole to pole during five two-year periods show a marked seasonal dependence. The surface temperature near the south pole over this time decreased by 2 K from 91.7 ± 0.3 to 89.7 ± 0.5 K while at the north pole the temperature increased by 1 K from 90.7 ± 0.5 to 91.5 ± 0.2 K. The latitude of maximum temperature moved from 19 S to 16 N, tracking the sub-solar latitude. As the latitude changed, the maximum temperature remained constant at 93.65 ± 0.15 K. In 2010 our temperatures repeated the north–south symmetry seen by Voyager one Titan year earlier in 1980. Early in the mission, temperatures at all latitudes had agreed with GCM predictions, but by 2014 temperatures in the north were lower than modeled by 1 K. The temperature rise in the north may be delayed by cooling of sea surfaces and moist ground brought on by seasonal methane precipitation and evaporation.

  5. Small Cold Temperature Instrument Packages

    Science.gov (United States)

    Clark, P. E.; Millar, P. S.; Yeh, P. S.; Feng, S.; Brigham, D.; Beaman, B.

    We are developing a small cold temperature instrument package concept that integrates a cold temperature power system with ultra low temperature ultra low power electronics components and power supplies now under development into a 'cold temperature surface operational' version of a planetary surface instrument package. We are already in the process of developing a lower power lower temperature version for an instrument of mutual interest to SMD and ESMD to support the search for volatiles (the mass spectrometer VAPoR, Volatile Analysis by Pyrolysis of Regolith) both as a stand alone instrument and as part of an environmental monitoring package. We build on our previous work to develop strategies for incorporating Ultra Low Temperature/Ultra Low Power (ULT/ULP) electronics, lower voltage power supplies, as well as innovative thermal design concepts for instrument packages. Cryotesting has indicated that our small Si RHBD CMOS chips can deliver >80% of room temperature performance at 40K (nominal minimum lunar surface temperature). We leverage collaborations, past and current, with the JPL battery development program to increase power system efficiency in extreme environments. We harness advances in MOSFET technology that provide lower voltage thresholds for power switching circuits incorporated into our low voltage power supply concept. Conventional power conversion has a lower efficiency. Our low power circuit concept based on 'synchronous rectification' could produce stable voltages as low as 0.6 V with 85% efficiency. Our distributed micro-battery-based power supply concept incorporates cold temperature power supplies operating with a 4 V or 8 V battery. This work will allow us to provide guidelines for applying the low temperature, low power system approaches generically to the widest range of surface instruments.

  6. Adaptive ultrasound temperature imaging for monitoring radiofrequency ablation.

    Directory of Open Access Journals (Sweden)

    Yi-Da Liu

    Full Text Available Radiofrequency ablation (RFA has been widely used as an alternative treatment modality for liver tumors. Monitoring the temperature distribution in the tissue during RFA is required to assess the thermal dosage. Ultrasound temperature imaging based on the detection of echo time shifts has received the most attention in the past decade. The coefficient k, connecting the temperature change and the echo time shift, is a medium-dependent parameter used to describe the confounding effects of changes in the speed of sound and thermal expansion as temperature increases. The current algorithm of temperature estimate based on echo time shift detection typically uses a constant k, resulting in estimation errors when ablation temperatures are higher than 50°C. This study proposes an adaptive-k algorithm that enables the automatic adjustment of the coefficient k during ultrasound temperature monitoring of RFA. To verify the proposed algorithm, RFA experiments on in vitro porcine liver samples (total n = 15 were performed using ablation powers of 10, 15, and 20 W. During RFA, a clinical ultrasound system equipped with a 7.5-MHz linear transducer was used to collect backscattered signals for ultrasound temperature imaging using the constant- and adaptive-k algorithms. Concurrently, an infrared imaging system and thermocouples were used to measure surface temperature distribution of the sample and internal ablation temperatures for comparisons with ultrasound estimates. Experimental results demonstrated that the proposed adaptive-k method improved the performance in visualizing the temperature distribution. In particular, the estimation errors were also reduced even when the temperature of the tissue is higher than 50°C. The proposed adaptive-k ultrasound temperature imaging strategy has potential to serve as a thermal dosage evaluation tool for monitoring high-temperature RFA.

  7. Dynamic temperature measurements with embedded optical sensors.

    Energy Technology Data Exchange (ETDEWEB)

    Dolan, Daniel H.,; Seagle, Christopher T; Ao, Tommy

    2013-10-01

    This report summarizes LDRD project number 151365, \\Dynamic Temperature Measurements with Embedded Optical Sensors". The purpose of this project was to develop an optical sensor capable of detecting modest temperature states (<1000 K) with nanosecond time resolution, a recurring diagnostic need in dynamic compression experiments at the Sandia Z machine. Gold sensors were selected because the visible re ectance spectrum of gold varies strongly with temperature. A variety of static and dynamic measurements were performed to assess re ectance changes at di erent temperatures and pressures. Using a minimal optical model for gold, a plausible connection between static calibrations and dynamic measurements was found. With re nements to the model and diagnostic upgrades, embedded gold sensors seem capable of detecting minor (<50 K) temperature changes under dynamic compression.

  8. Material Specific Design for Room Temperature Superconductivity

    Science.gov (United States)

    Isikaku-Ironkwe, O.-Paul; Ofe, Uko; Oriaku, Chijioke; Asiegbu, Dan; Oguzi, Emeka

    2012-02-01

    The transition temperature, Tc, of superconductors has been increased sevenfold from 23K in Nb3Ge to 164K in Hg-1223. A further two-fold increase would get us to above room temperature superconductivity. Studying high temperature superconductors (HTSCs), we have developed a formula that expresses Tc in terms of electronegativity, valence electrons, Ne, atomic number, Z, formula mass and a coupling constant, Ko. We observe an increasing linear relationship between Tc and Ko. Ko also correlates with formula mass and atomic number and the number of atoms in the compound. By our formula, Hg-1223 has Ko = 70. We propose, using our design algorithm, that room temperature superconductivity may be realized in a system with ko = 160; electronegativity = 2.5, Ne/Sqrt Z = 0.8. We proceed to show combinations of oxides and elements that will yield the required parameters for synthesizing reproducible room temperature superconductivity.

  9. Branching Fraction Measurements of the Decays B->EtaC K, where EtaC->K anti-K K Pi and EtaC->4K

    Energy Technology Data Exchange (ETDEWEB)

    London, Georges W

    2002-03-29

    In this report, we present the observation of the exclusive decays B{sup 0} {yields} {eta}{sub c}K{sup 0} and B{sup +} {yields} {eta}{sub c}K{sup +}, and the measurement of the related branching fractions. Using a sample of 22.7 x 10{sup 6} {Upsilon}(4S) {yields} B{bar B} decays collected with the BABAR detector at the SLAC PEP-II asymmetric B Factory during 1999-2000, we have observed statistically significant signals in the {eta}{sub c} {yields} K{sub S}{sup 0} K{sup {+-}}{pi}{sup {-+}} and K{sup +}K{sup -} {pi}{sup 0} channels and set upper limits in the {eta}{sub c} {yields} K{sup +}K{sup -}K{sup +}K{sup -} channels. All the results presented are preliminary. We have measured {Beta}(B{sup +} {yields} {eta}{sub c}K{sup +}) = (1.50 {+-} 0.19 {+-} 0.15 {+-} 0.46) x 10{sup -3}; and {Beta}(B{sup 0} {yields} {eta}{sub c}K{sup 0}) = (1.06 {+-} 0.28 {+-} 0.11 {+-} 0.33) x 10{sup -3} where the first error is statistical, the second systematic and the last due to the uncertainty on the world average {eta}{sub c} {yields} K{bar K}{pi} branching fraction.

  10. Temperature dependence and mechanism of the reaction between O(3P) and chlorine dioxide

    Science.gov (United States)

    Colussi, A. J.; Sander, S. P.; Fiedl, R. R.

    1992-01-01

    Second-order rate constants for the decay of O(3P) in excess chlorine dioxide, k(II), were measured as a function of total pressure (20-600 Torr argon) and temperature (248-312 K), using flash photolysis-atomic resonance fluorescence. Results indicate that k(II) is pressure dependent with a value, K(b), that is nonzero at zero pressure, and both the third-order rate constant and k(b) have negative temperature dependences.

  11. High Precision 40K/39K Ratio Determination

    Science.gov (United States)

    Naumenko, M. O.; Mezger, K.; Nagler, T. F.; Villa, I. M.

    2012-12-01

    Potassium is one of the eight most abundant chemical elements in the Earth's crust and a major element in many rock-forming minerals. The isotope 40K is radioactive and undergoes β- decay to 40Ca (ca. 89.3%) and electron capture to 40Ar (ca. 10.7%). Both decays can potentially be used as dating systems. The most commonly used branch is the decay of 40K to 40Ar because it can yield highly precise ages. Both decay schemes rely on the knowledge of the 40K branching ratio and the natural 40K abundance. A 40K abundance of 0.011672±41 % was measured on terrestrial material [1]. The relative uncertainty of 0.35 % has not been improved since. Recent improvements in the precision of mass spectrometric measurements have led to the situation that the uncertainties on the K decay constant and the abundance of 40K are a major source of uncertainty on the measured ages. A more precise definition of the 40K decay constant was attempted by different research groups within the last decade [2-9] but the goal of obtaining 0.1 % relative uncertainty on K-Ar ages for geological materials, as requested by the EARTHtime initiative, has not been achieved yet. In order to improve on this situation we studied the abundances of the K isotopes in terrestrial standards. A ThermoFischer Triton+ thermal ionisation mass spectrometer was used for K isotope ratio measurements of the NIST SRM 918b K standard loaded on Ta filaments with 0.1M phosphoric acid. Three techniques were applied: (A) dynamic measurement with in-run normalisation to the IUPAC value 41K/39K=0.072168; (B) a simple total evaporation procedure; (C) the "NBL-modified" total evaporation [10]. The 40K ion beam was measured in a Faraday cup with a 1E12 Ω resistor; 39K and 41K were collected in Faraday cups with 1E11 Ω resistors. Amplifier gains were intercalibrated by supplying fixed voltages off-line. Different measurement techniques were combined with different loading procedures. We also tested ionisation yields for the

  12. Uncertainty of a hybrid surface temperature sensor for silicon wafers and comparison with an embedded thermocouple.

    Science.gov (United States)

    Iuchi, Tohru; Gogami, Atsushi

    2009-12-01

    We have developed a user-friendly hybrid surface temperature sensor. The uncertainties of temperature readings associated with this sensor and a thermocouple embedded in a silicon wafer are compared. The expanded uncertainties (k=2) of the hybrid temperature sensor and the embedded thermocouple are 2.11 and 2.37 K, respectively, in the temperature range between 600 and 1000 K. In the present paper, the uncertainty evaluation and the sources of uncertainty are described.

  13. Rate constant and thermochemistry for K + O2 + N2 = KO2 + N2

    DEFF Research Database (Denmark)

    Sorvajärvi, Tapio; Viljanen, Jan; Toivonen, Juha

    2015-01-01

    in the form of double exponential decays of [K], which yielded both kR1 and the equilibrium constant for KO2 formation. kR1 can be summarized as 1.07 × 10-30(T/1000 K)-0.733 cm6 molecule-2 s-1. Combination with literature values leads to a recommended kR1 of 5.5 × 10-26T-1.55 exp(-10/T) cm6 molecule-2 s-1...... line width diode laser. Experiments were carried out with O2/N2 mixtures at a total pressure of 1 bar, over 748-1323 K. At the lower temperatures single exponential decays of [K] yielded the third-order rate constant for addition, kR1, whereas at higher temperatures equilibration was observed...

  14. Experimental and computational investigation of temperature effects on soot mechanisms

    Directory of Open Access Journals (Sweden)

    Bi Xiaojie

    2014-01-01

    Full Text Available Effects of initial ambient temperatures on combustion and soot emission characteristics of diesel fuel were investigated through experiment conducted in optical constant volume chamber and simulation using phenomenological soot model. There are four difference initial ambient temperatures adopted in our research: 1000 K, 900 K, 800 K and 700 K. In order to obtain a better prediction of soot behavior, phenomenological soot model was revised to take into account the soot oxidation feedback on soot number density and good agreement was observed in the comparison of soot measurement and prediction. Results indicated that ignition delay prolonged with the decrease of initial ambient temperature. The heat release rate demonstrated the transition from mixing controlled combustion at high ambient temperature to premixed combustion mode at low ambient temperature. At lower ambient temperature, soot formation and oxidation mechanism were both suppressed. But finally soot mass concentration reduced with decreasing initial ambient temperature. Although the drop in ambient temperature did not cool the mean in-cylinder temperature during the combustion, it did shrink the total area of local high equivalence ratio, in which soot usually generated fast. At 700 K initial ambient temperature, soot emissions were almost negligible, which indicates that sootless combustion might be achieved at super low initial temperature operation conditions.

  15. Subspace K-means clustering.

    Science.gov (United States)

    Timmerman, Marieke E; Ceulemans, Eva; De Roover, Kim; Van Leeuwen, Karla

    2013-12-01

    To achieve an insightful clustering of multivariate data, we propose subspace K-means. Its central idea is to model the centroids and cluster residuals in reduced spaces, which allows for dealing with a wide range of cluster types and yields rich interpretations of the clusters. We review the existing related clustering methods, including deterministic, stochastic, and unsupervised learning approaches. To evaluate subspace K-means, we performed a comparative simulation study, in which we manipulated the overlap of subspaces, the between-cluster variance, and the error variance. The study shows that the subspace K-means algorithm is sensitive to local minima but that the problem can be reasonably dealt with by using partitions of various cluster procedures as a starting point for the algorithm. Subspace K-means performs very well in recovering the true clustering across all conditions considered and appears to be superior to its competitor methods: K-means, reduced K-means, factorial K-means, mixtures of factor analyzers (MFA), and MCLUST. The best competitor method, MFA, showed a performance similar to that of subspace K-means in easy conditions but deteriorated in more difficult ones. Using data from a study on parental behavior, we show that subspace K-means analysis provides a rich insight into the cluster characteristics, in terms of both the relative positions of the clusters (via the centroids) and the shape of the clusters (via the within-cluster residuals).

  16. Measurement of CP asymmetry in D-0 -> K- K+ decays

    NARCIS (Netherlands)

    Aaij, R.; Dufour, L.; Mulder, M; Onderwater, C. J. G.; Pellegrino, A.; Tolk, S.; van Veghel, M.

    2017-01-01

    A measurement of the time-integrated CP asymmetry in the Cabibbo-suppressed decay D-0 -> K- K+ is performed using pp collision data, corresponding to an integrated luminosity of 3 fb(-1), collected with the LHCb detector at centre-of-mass energies of 7 and 8 TeV. The flavour of the charm meson at

  17. Results from Super-Kamiokande and K2K

    Indian Academy of Sciences (India)

    drawing are large enough for full-sized trucks to drive through. The curving tunnel on the right side of the sketch contains our water purification plant; just above that is our main control room. Figure 2. The KEK to Kamioka (K2K) experiment. production region, is used to normalize the neutrino flux. Deviations in the number of.

  18. Fully Funding Pre-K through K-12 Funding Formulas

    Science.gov (United States)

    Barnett, W. Steven; Kasmin, Richard

    2018-01-01

    Pre-K is widely acknowledged to be a sound public investment. When their pre-K programs are of high quality, disadvantaged children see particularly large benefits--higher test scores, less need for grade repetition and special education, and increased educational attainment. Yet high-quality programs are in short supply. State boards of education…

  19. Calculation of K diffusional rates in bentonite beds

    Energy Technology Data Exchange (ETDEWEB)

    Altaner, S.P. (Univ. of Illinois, Urbana (USA))

    1989-04-01

    Zoned K-bentonites with illite-rich contacts and smectite-rich interiors are interpreted as products of potassium (K) metasomatism during diagenesis. A mathematical model is developed to describe both K transport in pore water and K fixation in smectite clays (smectite illitization). Solution of these coupled equations is done using finite difference techniques. Best-fit modeling of mineralogical and K/Ar data from a 2.5 m thick zoned K-bentonite from western Montana suggests that diffusional exchange of K for Ca is the important transport mechanism in compacted bentonite beds. Diffusion coefficients (D) for K/Ca exchange of about 9 to 13 {center dot} 10{sup {minus}8} cm{sup 2}/sec best model observed zonations in the 2.5 m bentonite as well as mineralogical zonations observed in bentonites thinner than 2.5 meters. This range in D seems to be reasonable when compared with calculated D values for K/Ca exchange in a highly tortuous medium. Although the precise burial history for these Montana rocks is not well known, geologically reasonable burial histories appear to be best modeled by using fifth- and sixth-order kinetic parameters for illitization. The model suggests that illitization occurred for 7 to 9 my at temperatures of about 80 to 90{degree}C. The model of chemical transport and illitization developed here should have applications in the analysis of the stability of bentonite as a backfill material in a nuclear waste repository.

  20. Study of CP violation in Dalitz-plot analyses of B0 to K K-KS, B to K K-K , and B to KSKSK

    Energy Technology Data Exchange (ETDEWEB)

    Lees, J.P.

    2012-03-20

    We perform amplitude analyses of the decays B{sup 0} {yields} K{sup +}K{sup -}K{sub s}{sup 0}, B{sup +} {yields} K{sup +}K{sup -}K{sup +}, and B{sup +} {yields}, and measure CP-violating parameters and partial branching fractions. The results are based on a data sample of approximately 470 x 10{sup 6} B{bar B} decays, collected with the BABAR detector at the PEP-II asymmetric-energy B factory at the SLAC National Accelerator Laboratory. For B{sup +} {yields} K{sup +}K{sup -}K{sup +}, we find a direct CP asymmetry in B{sup +} {yields} {phi}(1020)K{sup +} of A{sub CP} = (12.8 {+-} 4.4 {+-} 1.3)%, which differs from zero by 2.8{sigma}. For B{sup 0} {yields} K{sup +}K{sup -}K{sub s}{sup 0}, we measure the CP-violating phase {beta}{sub eff} ({phi}(1020)K{sub s}{sup 0}) = (21 {+-} 6 {+-} 2){sup o}. For B{sup +} {yields} K{sub s}{sup 0}K{sub s}{sup 0}K{sup +}, we measure an overall direct CP asymmetry of A{sub CP} = (4{sub -5}{sup +4} {+-} 2)%. We also perform an angular-moment analysis of the three channels, and determine that the f{sub X}(1500) state can be described well by the sum of the resonances f{sub 0}(1500), f{prime}{sub 2}(1525), and f{sub 0}(1710).